If your free chlorine level is lower than 1 part per million (or ppm), then you need to take action to raise your chlorine levels. Chlorine levels at or below 1 ppm mean your pool water isn’t sanitized, which can lead to algae growth and bacteria build-up.

But what if you’ve added chlorine tablets or granules and the levels won’t change? How do you raise free chlorine in a pool if you’ve already added chlorine?

If your chlorine levels are low (1 ppm) or you’re not getting a chlorine reading at all (0 ppm), shock your pool water with a chlorine-based shock.

But if your chlorine levels continue to remain low, even after shocking, you may have a high chlorine demand issue.

Keep reading for a step-by-step guide on what causes low chlorine levels and how to raise free chlorine levels in your pool.

What is Free Chlorine?

Free chlorine is the amount of chlorine that’s available to sanitize your pool water. In other words, it’s the chlorine that hasn’t been used up and is still free to kill contaminants. If there isn’t enough free chlorine in your water, bacteria and other harmful microorganisms can build up. Your free chlorine levels should be between 1 and 3 ppm.

On the other hand, combined chlorine (a.k.a. chloramines) is chlorine that’s already been used up to fight contaminants in the water. Your combined chlorine level should be no more than 0.5 ppm. If the amount of combined chlorine gets too high, your chlorine will stop working effectively and it will produce that classic chlorine smell.

Finally, total chlorine is the sum of free chlorine and combined chlorine. If the total chlorine levels are the same as the free chlorine levels (like 3 ppm), it means none of the chlorine has been used up (combined chlorine) and it’s available to work as a sanitizer.

If you’re still feeling confused about water chemistry, you’re not alone. Check out our Pool Care Video Course for a complete guide on everything you need to know about pool maintenance.

What Causes Low Free Chlorine Levels?

The first step in raising the free chlorine in your pool is knowing what caused it. And there are several factors that can contribute to sudden or chronically low free chlorine levels.

High Chlorine Demand

Chlorine can only sanitize so much. If you have a high bather load or a lot of debris in the water, you’ll need more chlorine to sanitize the water effectively. The more contaminants you have to fight in the water, the more chlorine your pool water will demand.

Chlorine demand is most common when your pool water sits untreated and stagnant for the winter. Heavy rainfall can also lead to chlorine demand, especially if you experience runoff from your yard.

If you just added chlorine or a chlorine-based shock to your pool and you still have a low chlorine level, there’s a chlorine demand problem.

In order to cure chlorine demand, triple shock your pool with calcium hypochlorite or cal-hypo shock. Add three pounds of shock for every 10,000 gallons of water in your pool.

Heavy Pool Use

The more swimmers you have in the pool and the more often you use it, the more contaminants your chlorine will need to fight. Things like sunscreen, dirt and even the oil from your skin can cause your chlorine to work over time.

Shock your pool weekly and especially after parties to keep your free chlorine levels high and your water sanitized.

Sunlight and Low Cyanuric Acid Levels

If you’re using unstabilized chlorine (like liquid chlorine or bleach) to sanitize your water, your chlorine levels will drop in the sunlight. That’s because the sun’s rays will break down your chlorine if it doesn’t have any stabilizer (a.k.a. cyanuric acid).

Test your cyanuric acid levels regularly and use a chlorine stabilizer to keep your chlorine from breaking down in the sunlight.

Very High Cyanuric Acid Levels

When your CYA levels are too high, it can hamper your chlorine’s effectiveness. High CYA will weaken your chlorine’s ability to sanitize your water. If you use 3-Inch chlorine tablets (trichlor pucks), it will consistently raise your cyanuric acid.

Regularly test your CYA levels and make sure that it stays within the correct range of 30 and 50 ppm.

Increased Organic Contaminants

A heavy rain storm can increase the contaminants in your pool water, And that can quickly use up your free chlorine as it binds to everything in an effort to sanitize the water.

Be sure to clean debris from your water after a storm and shock your pool, especially if you’ve experienced runoff.

Refilling the Pool with Fresh Water

If you’ve just added fresh water to your pool, it could disrupt your water chemistry. More fresh water means less sanitized, balanced water with the proper amount of pool chemicals.

Not Adding Enough Chlorine

One of the simplest reasons behind low free chlorine levels is that there’s not enough chlorine regularly added to the water. If you’re adding chlorine tablets to your skimmer but your pump shuts off, that chlorine won’t get into the water. And if you use a chlorine floater, make sure you have enough chlorine in it to cover your surface area.

Not Enough Salt in Your Salt Water Pool

If you use a saltwater generator and your chlorine levels are low, your pool may not have enough salt. Your salt cell needs a certain level of salinity to function.

Test your pool salinity every month to make sure your salt levels are within range. And be sure to regularly inspect your salt water generator to make sure it’s working properly.

How to Raise Free Chlorine in a Pool

If you’ve not cleaned your pool yet and there’s a lot of debris, your free chlorine level is likely low because it’s busy working on cleaning all the contaminants from the debris. Clean your pool and remove debris, then test the chlorine level.

Then, test your water. You’ll want to make sure your pH, alkalinity, and cyanuric acid levels are within range. If you need help balancing your water chemistry, be sure to check out our guides on pH and cyanuric acid.

Once your pool is free of debris and your other levels are balanced, it’s time to shock your water.

When you shock your pool, you’re adding enough chlorine to reach a “chlorine breakpoint.” This raises your pool’s free chlorine levels to 10 times or more over the normal amount.

There are multiple types of chlorine pool shock and each one can affect the other pool chemicals in the water, like your pH levels. Keep in mind that using a non-chlorine shock will decrease your combined chlorine but it will not raise your free chlorine level. That’s because the oxidation in a non-chlorine shock helps break up contaminents without adding chlorine.

• For Traditional Chlorine Pool Owners: Use Cal-Hypo Shock. Cal-hypo is the strongest type of chlorine shock available and will help quickly raise your free chlorine levels. Because cal-hypo shock is unstabilized chlorine, you’ll need to add it to your pool at night to avoid the sun’s UV rays destroying your shock. Then wait at least 8 hours before swimming again. If you suspect you have high chlorine demand (lots of contaminants and a reading of 0 ppm), you’ll need to triple shock your pool.
• For Salt Water Pool Owners: Use Sodium Dichlor Shock. Dichlor shock will help raise your chlorine without causing scale buildup on your saltwater generator. But it will also raise your cyanuric acid (CYA) levels. So if you’re already dealing with high CYA levels, opt for liquid chlorine.

What If Your Free Chlorine Levels Don’t Change After Shocking?

There are several reasons why your free chlorine levels are still low after shocking your water:

• Other pool chemicals are out of balance: Without the right amount of pH or cyanuric acid in your water, your chlorine levels can fluctuate.
• High contaminant load: You may have a build-up of bacteria or algae that requires a more aggressive shock treatment. If your pool looks dusty on the bottom or clouds up when you brush it, it’s likely mustard algae.

What if Your Free Chlorine Levels are Constantly Low?

If you find that you’re consistently getting low chlorine readings, check your cyanuric acid level. Low CYA means that your chlorine is susceptible to the sun’s UV rays. So your chlorine will burn up faster.

On the other hand, you may have high chlorine demand. Your chlorine’s effectiveness is finite. So if there are lots of swimmers or debris and organic contaminants in the water, more chlorine is required to properly sanitize the water. At a certain point, your chlorine gets used up faster than you can add it and your levels remain low. Again, shocking your pool can help fix this.

On the other hand, if you have constantly low chlorine levels in a saltwater pool, you likely need to add more pool salt or clean or replace your salt cell.

Frequently Asked Questions About How to Raise Free Chlorine in a Pool

Need more help figuring out how to raise free chlorine in a pool? Here are some common questions and answers.

What do I do if my free chlorine is too low?

If your levels are low, start by simply adding more chlorine. Use test strips or a liquid testing kit to determine the current level. Then add chlorine granules to raise the levels quickly. If that doesn’t work, shock your pool.

How much shock do I need to raise free chlorine?

When shocking your pool, the goal is to significantly and quickly raise your free chlorine levels above your combined chlorine levels. If you’re using cal-hypo shock, use 1 pound bag per 10,000 gallons of water.

Does chlorine-free shock raise free chlorine?

Non-chlorine shock will not add chlorine to your pool, and therefore, will not raise free chlorine levels. However, non-chlorine shocks will remove chloramines, a.k.a. combined chlorine.

What is more important: your free chlorine or total chlorine levels?

Both are important, but what matters is that your free chlorine levels are always higher than your combined chlorine levels. If the free chlorine level is low and the combined level is high, then you don’t have enough available chlorine to adequately sanitize your pool. Total chlorine accounts for both free and combined chlorine.

Is it safe to swim in a pool with low chlorine?

Technically, you could swim in a freshly filled pool with low chlorine. But contaminants will build up quickly in the water. And continuously using a swimming pool with a low level of chlorine could cause illness and eye or skin irritation. It’s always better to balance pool chemicals and swim in a pool with adequate chlorine.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post How to Raise Free Chlorine Levels in a Pool appeared first on Swim University®.

Regular pool water testing is a crucial part of pool maintenance. But there are very different testing methods that provide different and sometimes more accurate results. So what’s the best way to test your water: test strips, liquid test kits, or a digital test reader?

• Test strips are the most cost-effective and easiest way to test your pool water. But they’re limited in what they measure and they can be contaminated easily if they’re left unsealed or exposed to moisture.
• Liquid test kits offer a broader range of testing options. But they require precision when adding liquid reagents, otherwise, you could get inaccurate results.
• Digital readers are fast, accurate, and great for anyone who has trouble reading color. However, they’re more expensive than other types of pool test kits.

That said, if you’re looking for something to help you with easy, weekly water testing, we recommend the very popular AquaChek Select Connect 7-Way Pool & Spa Test Strips.

On the other hand, if you’re in the market for a more comprehensive pool water testing kit, we recommend the Taylor Complete Pool and Spa Liquid Test Kit.

Finally, if you prefer a digital reader or you’re having trouble interpreting the color-coded charts on other kits, check out the LaMotte Digital Reader.

Keep reading for more information about each type of test kit and the brands we recommend.

Best Test Strips: AquaChek 7-Way Pool & Spa Test Strips

AquaChek test strips are an easy-to-use, 7-way test kit that measures the more important pool chemistry levels: pH, total chlorine, free chlorine, bromine, alkalinity, total hardness, and cyanuric acid. So if you’re looking for the easiest way regularly test things like your chlorine levels, this is a great option. These strips also include a free mobile app to help you interpret your results. Overall, AquaChek’s popular and affordable test strips are perfect for regular, weekly pool maintenance and testing.

Best Liquid Test Kit: Taylor Complete Pool and Spa Test Kit

Taylor Complete Pool and Spa Liquid Test Kit tests for all of your important levels, including chlorine, bromine, pH, acid demand, and total alkalinity. This kit includes rapid dissolve tablets to test for free chlorine, and liquid solutions to test for all other levels. And different versions of this kit also include a FAS-DPD bromine test.

Most importantly, Taylor Technologies is one of the most reliable and best pool testing options on the market. However, this kit does not test salt levels, so you’ll need to purchase a salinity meter separately. And the reagents that measure your levels are very accurate when fresh, so the kit will need to be stored in a temperature-controlled environment. Also, you’ll need to replace or refill your kit components, like Phenol Red and Orthotolidine (OTO), as you use the kit.

Best Digital Test Kit: Lamotte Digital Reader and Test Kit

If you don’t want to do any color matching, the Lamotte Digital Reader can help. This is the ideal option for those who have difficulty distinguishing color and want more definitive results. The reader runs on 2AA batteries (not included) and features a memory function that lets you store the last nine test results.

Additionally, this digital water tester features a water-resistant LCD display, so you don’t have to worry about the pool water damaging the unit. In general, digital testers are more expensive than testing strips or liquid test kits. But they give pool owners a simple, fast, and reliable water testing solution.

What Are the Correct Pool Water Chemistry Levels?

Regardless of which type of testing kit you use, your normal pool water chemistry levels should be:

• pH: 7.4-7.6
• Total Alkalinity: 100-150 ppm
• Free Available Chlorine: 1-3 ppm
• Bromine: 3-5 ppm
• Cyanuric Acid: 30-50 ppm
• Calcium Hardness: 200-400 ppm
• Metals: 0 ppm
• Phosphates: 0 ppm
• Total Dissolved Solids (TDS) for Non-Salt Water Pools: 0-2500 ppm

By the way, if you’re feeling confused about pool chemistry, you’re not alone. That’s why we made our Pool Care Video Course so you never have to feel confused about your chemical levels again. Check it out!

Test Strips vs. Liquid Test Kits: Which Is Better?

While we recommend having both a liquid test kit and a supply of test strips on hand, here are the biggest pros and cons of each.

Pool Test Strips: Pros and Cons

Test strips are incredibly easy to use and the most affordable water testing option. But while they’re generally very accurate, they test for fewer chemicals than liquid test kits. To get the most accurate results, use strips before they expire and store them away from moisture. And avoid touching the ends of the strips before you use them to prevent contamination.

Liquid Test Kits: Pros and Cons

On the other hand, liquid test kits provide a more accurate and comprehensive test. Once you collect your water sample, you’ll add a set amount of special chemical drops (known as reagents) into each test kit vial. Then compare the color of the water sample to the color chart. But since you’ll need to repeat the steps for each chemical you’re testing for, this kind of testing takes more time than using a test strip. Also, if you accidentally add too much of each reagent, your test results for the respective chemical levels are inaccurate.

Purchasing a liquid test kit is more expensive than buying test strips. But when used correctly – that is, with the correct amount of each reagent added to your vial of pool water – your results will be highly accurate. However, you’ll need to regularly replace your drops. Similarly to test strips, the reagants and drops in the kit will expire.

Frequently Asked Questions About Pool Test Kits

Need more help deciding between pool test kits? Here are some commonly asked questions and answers.

What is the most accurate way to test your pool?

Test strips provide a quick and easy way to test your swimming pool chemicals and get a general understanding of your water levels. But liquid testing kits, when used correctly, provide more comprehensive and accurate results than test strips. However, if you mess up when adding liquid reagents to your pool water sample, you risk getting inaccurate results.

So if you’re looking for a kit to perform simple, weekly chlorine tests or pH tests, test strips will work fine.

Are pool water test strips accurate?

Yes, pool water test strips are accurate. All you have to do is dip the strip into the water and allow the strip to rest for 15 seconds before interpreting the results.

How can I test my pool water at home?

You can test your pool water at home using test strips or a liquid pool water test kit. At a minimum, the kit should test chlorine and pH levels. But you can get more specialized kits to test for metals. However, if your levels are “off the chart” or you’re worried you’re not getting accurate results, consider bringing a water sample to a local pool supply store.

What does a pool test kit test for?

Most pool test kits will test for the standard chlorine, pH, and total alkalinity. But other pool testing strips are available for additional factors, such as total dissolved solids (TDS), salt, calcium hardness, potential contaminants, bacteria, phosphates, and more.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post Best Pool Test Kits for the Most Accurate Water Readings appeared first on Swim University®.

A salt water system is a great investment if you’re tired of buying and adding chlorine and you’re looking to spend less time managing your pool water chemistry. But before you buy a salt water chlorinator (also known as a salt water generator), there are a few things to keep in mind:

• Salt water pools are still chlorine pools. The salt water generator converts salt into chlorine. So instead of adding chlorine directly to your water, you’re adding salt.
• You’ll save money on chemicals, but you’ll spend more money on equipment. The units themselves usually cost over $1,000 and you’ll need to buy replacement salt cells every 5 years.
• You won’t need to buy, handle or add chlorine ever again. You’ll never have to add weekly doses of chlorine to your pool! But you’ll still need to test your water chemistry and keep an eye on your salt water generator to make sure it’s working properly.

With that in mind, if you’re in the market for a salt water system, we recommend the Hayward Salt Chlorination System. It has one of the longest lifespans compared to other units and you’ll get full control over your chlorine output levels.

However, if you have limited space to install your salt system, the Pentair IntelliChlor is an alternative, more compact option. Just keep in mind that its replacement parts are more expensive. Finally, if you have a smaller above ground pool and you’re looking for a budget-friendly salt system, check out the Krystal Clear Intex Salt Water System.

Keep reading for more information about each option and whether or not a salt water system is worth it for your pool.

The Best Salt Water Pool Systems

No matter what type of salt water system you choose, always purchase from a reputable brand and look for salt water generators that come with a decent warranty. You’ll need to replace your salt cell every 5-7 years, so you’ll want to make sure you’re able to find replacement parts in the future. Finally, before making any purchase, double-check for compatibility with your pool and plumbing setup.

Best Overall: Hayward Salt Chlorination System

This Hayward Salt Water System is ideal for inground pools up to 40,000 gallons. Installation is relatively easy and the digital display makes it simple to adjust your chlorine output. It works well with other pool automation systems to allow you more customizable programming options. And it includes the Hayward TurboCell Salt Chlorination CELL-15, which comes with a 3-year warranty.

The only downside to this system is that it takes up more room than other salt chlorine generators. But if you can find the space, the Hayward Salt Water System is worth it for its longevity and ease of use.

Runner Up: Pentair IntelliChlor Salt Chlorine Generator

Because of its compact size, the Pentair IntelliChlor is easy to install in almost any pool plumbing set up. It features an easy-to-view display so you can keep an eye on salt levels, cell condition, and water cleanliness. It’s also available in multiple models, making this a flexible choice for all pool sizes, working with both smaller pools (up to 20,000 gallons) and larger pools (up to 60,000 gallons).

However, you will need to purchase an IntelliChlor power center, sold separately, to make this unit work. And because this is an “all-in-one” unit, the replacement cells cost more compared to other salt water systems. So expect to spend more money in the future compared to other salt water chlorinators.

Best Budget: Intex Krystal Clear

The Intex Krystal Clear Salt Water System is a popular, affordable option for above ground, small pools up to 15,000 gallons. Whether you have a new or existing pool, you can install it with no additional plumbing required. It comes with adapters that allow you to add it to other types of pools beyond Intex. And it features a programmable digital timer that lets you easily control chlorine output.

However, it can be more challenging to find replacement parts with this brand. And it does require you have a pump installed with a flow rate of at least 700 gallons per hour (GPH).

How Does a Salt Water Pool System Work?

A salt water pool still sanitizes your water with chlorine, just like a traditional pool. But instead of purchasing and adding chlorine to your water, you use pool-grade salt, sodium chloride.

The generator uses electrolysis to separate the salt in the pool water into two primary components, one of which is chlorine. But even after the chlorine is made, the salt stays in the water and gets recycled and reused by the salt water chlorinator.

Salt water swimming pools generally need salt levels of 3,000 parts per million (PPM) before the generator will start working. That’s the same salinity as human tears, so your pool water won’t be salty like ocean water.

By the way, if you have other questions about pool chemistry and pool maintenance, check out our Pool Care Video Course.

How Much Does a Salt Water System Cost?

On average, most high-quality salt water chlorinators cost over $1,000. You’ll also have the cost of salt cell replacements about every 5 years, which can cost several hundred dollars. The larger your pool, the more expensive your salt water system will be.

Are Salt Water Systems Worth It?

With a salt water system, you never have to worry about buying, handling, and adding chlorine again. And salt water chlorinators produce a steadier, more consistent flow of chlorine in your pool water. That means you’re more likely to avoid algae issues, contaminant build-up, and chloramines (the byproduct of used-up chlorine). That means no chlorine-like smell and less skin and eye irritation for swimmers.

Salt water systems also require less hands-on chemical maintenance. Instead of manually adding chlorine granules or liquid, simply add salt to your pool water and your chlorine generator creates a steady, consistent flow of chlorine. And salt water systems include flow switches to control chlorine output.

Finally, buying and using salt is much cheaper than chlorine. A salt chlorine generator produces chlorine at approximately $1/pound. Whereas purchasing chlorine at your local pool supply store puts it at $2 to $4 a pound.

That said, of course, salt water pool systems aren’t the ideal choice for all pool owners. They do come with a higher initial investment (over $1,000 before installation). And you’ll also have to pay for a salt cell replacement about every 5 years. And that can cost several hundred dollars. But again, you’ll be spending less money each year on chlorine.

Also, any build-up of salt will corrode pool equipment, especially any metal that’s in or around your pool. This includes screws, heaters, lights, patio furniture, and diving board attachments. And salt water splash out is corrosive if it builds up on pool landscaping or coping.

But overall, a salt water system is a great investment for any pool owner looking to avoid handling and adding chlorine to their water while keeping their pool consistently sanitized.

Frequently Asked Questions About Salt Water Pool Systems

Need more help deciding if a salt water generator is right for your pool? Here are some commonly asked questions and answers.

What are the disadvantages of salt water pools?

Because salt water pools are more complex to maintain than traditional pools, they may require experienced technicians to take care of even minor issues. And if salt builds up on equipment or surfaces, it can erode your pool equipment and parts. That includes pool heaters, pool lights and fixtures, liners, and masonry work around the edge of your pool.

Is it cheaper to run a salt water pool compared to a chlorine pool?

Pool salt costs significantly less than chlorine and you’ll likely only need to add it to your water once or twice a year. But you’ll likely have higher electricity costs because you’re running a salt water generator. A 20,000-gallon salt water pool uses an additional 500 watts of electricity to power the salt water generator. That translates to around $40 to $50 more a year in electric costs. But you’ll likely save that amount of money (or more) by not having to buy chlorine.

Are salt water pools hard to maintain?

No, salt water pools are not hard to maintain but the equipment itself (the salt water chlorinator) may require professional maintenance and repair. But while you may need to hire out help for the salt water system itself, you won’t have to deal with buying, storing, and adding chlorine to your pool water.

Can you switch from chlorine to salt water pool?

Yes, it’s very simple to convert a traditional chlorine pool to a salt water pool. All you have to do is install the chlorination system and add pool salt to the water. From there, the generator will produce chlorine for you. Remember, chlorine is the sanitizer in both pools! For a step-by-step guide, be sure to check out our guide on Salt Water Pool Conversion.

Do salt water pools get algae?

Salt water pools are still susceptible to algae blooms, but the continuous and steady supply of chlorine from the salt chlorine generator should help prevent green water. Most generators have a super chlorination feature to increase your chlorine level and kill contaminants. But you may need to shock your pool if you’re already dealing with a significant algae issue.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post Salt Water Pool Systems: What’s the Best One and Are They Worth It? appeared first on Swim University®.

Testing your pool water regularly is an essential part of pool maintenance. It’s how you know your chemical balance is where it should be. But, unless you know when and how to use pool test strips, you could be misinterpreting your water test results.

Watch the video below for how to test your water. Or keep reading for a complete guide on when to use test strips, and how test trips compare to liquid test kits.

How to Use Pool Test Strips

Test strips are the quickest and easiest way to test your pool water. And they’re an essential item to have on hand for regular pool maintenance.

Most pool test strips test total hardness, total chlorine, total bromine, free chlorine, pH, total alkalinity, and cyanuric acid (or CYA). These worth as both pool and spa test strips. You can also find specialty test strips that check for metals like copper and iron or salt levels for saltwater pools.

We recommend testing your pool water chemistry once a week. But you may need to test more often if you’re dealing with cloudy water, algae, or any water clarity issues. It’s also a good idea to test in unusually warm weather or after a storm.

By the way, if you feel really confused with pool water chemistry, be sure to check out our Pool Care Video Course.

1. Collect a Pool Water Sample

Before you collect the sample, turn your pump on high and let the water circulate for at least an hour. If you test stagnant water, the results may not be as accurate.

Using a clean, glass cup, reach your arm into your pool elbow deep and collect some pool water. Avoid collecting surface water or water near floating chemical dispensers or pool returns, since this may affect the accuracy of your test results.

2. Dip the Test Strip into the Water

Dip the pool test strip into the water and quickly remove it. There’s no need to keep it submerged or soak it in the water. Just make sure your finger doesn’t go into the water.

3. Allow the Test Strip to Develop and Measure Results

Hold the strip in the air for about 15 seconds. Do not shake it. Then hold the strip next to the test packaging to compare the color chart. Match it up to see where your levels are.

4. Adjust Your Pool Chemicals Accordingly

Use the colored chart on the pool water test strips packaging to determine what chemicals need balancing. You’ll want to adjust your water chemistry based on the normal ranges for each chemical. Here are the pool chemical levels we recommend:

• pH: 7.4-7.6
• Total Alkalinity: 100-150 ppm
• Free Available Chlorine: 1-3 ppm
• Bromine: 3-5 ppm
• Cyanuric Acid (Stabilizer): 30-50 ppm
• Calcium Hardness: 200-400 ppm

For more help with balancing your pool chemicals, check out our guide to Basic Pool Chemistry 101.

Pool Test Strips vs. Liquid Test Kit: Which One is Better?

Test strips are a quick and convenient way to do weekly water testing, especially to keep track of fluctuating sanitizer or pH levels. And test strips are much more affordable than liquid test kits. But it’s easy to spoil an entire pack if they become damp or are left out in the sunlight too long. And the strips do expire.

Liquid test kits are typically more precise when used correctly. And because testing is available for a broader range of chemicals, they are the only option available when testing for certain levels.

But because the tests are more complex, there’s always more room for human error. And they are much more expensive. Finally, the chemical reagents used in these kits do expire, so you will need to replace them periodically to ensure the tests remain accurate.

So while liquid test kits are often a more accurate and complete testing solution than test strips, there’s more expensive and cumbersome. Pool test strips are a great and essential item to have on hand for regular pool maintenance.

Frequently Asked Questions About Pool Test Strips

Need more help with test strips? Here are some common questions and answers.

Do swimming pool test strips work?

Yes, pool strips are a reliable way to test your pool water chemistry. The most common pool test strips are either 4-way or 6-way test strips that measure things like pH, alkalinity and free chlorine levels. These testers can be used in both inground and above ground pools.

Which pool test strips are the best?

We recommend using AquaChek Pool & Spa Test Strips. AquaChek is a very reliable brand used by many pool owners and pool professionals.

How long do you leave pool test strips in the water?

You do not need to leave test strips submerged in the water. A quick dip and release from the water is all it takes. Allow 15 seconds for the color to develop on the strip before comparing it for results purposes.

What happens if I can’t get an accurate reading?

If you suspect your pool water test kit isn’t measuring your levels correctly, you may need to bring a water sample to your local pool store. This can happen when your levels are “off the charts.” Your pool store can do more comprehensive chemical testing and provide you with accurate results.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post Pool Test Strips: How to Use Them the Right Way appeared first on Swim University®.

Adding shock to your water is an important part of pool maintenance, but it can be hard to know confidently when it’s okay to swim again. Should you wait an entire day after shocking your water? And how do you know the shock is actually dissolved and it’s truly safe for swimmers?

How long to wait to swim after shocking your pool depends on what type of shock you use: chlorine vs. non-chlorine. You can swim shortly after using non-chlorine shock in your water. But as a rule of thumb, you should wait at least 8 hours to swim after adding chlorine shock to your pool water. You’ll know it’s safe to swim if your free chlorine levels have dropped down to the normal range of 5 ppm (parts per million) or less.

So be sure to test your water before and after shocking your pool and make sure your filter is running to circulate the water after you’ve added shock.

How Long Does Shock Take to Dissolve?

Most other pool chemicals that adjust levels, like alkalinity, pH, and calcium hardness, dissolve in your pool water in under an hour. But because chlorine-based pool shock is a powerful, highly concentrated dose of chlorine, it takes longer to work in the water.

The goal of adding chlorine shock, like cal-hypo shock or dichlor, is to quickly elevate your chlorine levels. This removes algae, chloramines, and other contaminants by raising your chlorine levels above 10 ppm in a short period of time. And while that high chlorine concentration is great for killing algae and getting rid of chloramines, it’s not safe to swim in. That’s why you need to wait at least 8 hours after adding shock to your water or whenever your chlorine levels drop back to a safe range (ideally 3 ppm, or under 5 ppm). After shocking your pool, always retest your water chemistry by using either a test kit or test strips.

By the way, if you’re still feeling confused about pool chemistry, you’re not alone! Be sure to check out our comprehensive Pool Care Video Course.

When Should You Shock Your Pool?

Shocking helps by balancing pool water after contamination, like after a pool party or after heavy rain. It also prevents algae growth and is a more effective treatment than algaecide if you already have a significant algae bloom.

Pool shock also helps remove chloramines, or combined chlorine, and helps revitalize your existing chlorine. That means your regular chlorine can continue to do its job of sanitizer your water.

What Type of Shock Should You Use?

If you’re dealing with a significant water problem, we recommend using a chlorine-based shock, like calcium hypochlorite (cal-hypo) or dichlor shock. The powerful concentration of chlorine will help kill contaminants and algae. But because they will significantly increase the amount of chlorine in your water, your pool won’t be safe to swim in until your chlorine levels drop back down.

If you’re looking for a shock for regular maintenance or to refresh your sanitizer, use a non-chlorine shock. Also known as oxidizers, non-chlorine shocks allow you to go back to swimming shortly after it’s added to the water. That’s because it won’t affect your chlorine levels. But while this type of shock will help bring balance back to your water, it’s usually not powerful enough for pool owners dealing with major issues like algae.

What Should You Do After Shocking Your Pool?

Once you’ve shocked your pool, allow your filter to circulate the water. Keep the pump running for at least 8 hours after shocking. And remember, always add shock at night if you’re using an unstabilized shock, like cal-hypo. Otherwise, the shock will burn off from the sun.

And if you need a step-by-step walkthrough on how to add shock to your pool water, check out our guide on How to Shock a Pool the Right Way.

Frequently Asked Questions About Shocking Pool

Need more help understanding pool shock? Here are some frequently asked questions and answers.

Can you swim in the pool after you shock a pool?

You need to wait for at least 8 hours and up to 24 hours after using a chlorine-based shock before you can swim. And you’ll want to retest your water to make sure your chemical levels are within range. If your free chlorine is at or below 5 ppm and your pH levels are at or below 7.6, it’s likely safe to swim. But always follow the manufacturer’s directions regarding wait times after adding shock.

What happens if you go in a pool that was just shocked?

If you use a pool after adding high contractions of bleach, liquid chlorine, or another type of chlorine-based shock, you may experience skin and eye damage. Chlorine shock and large concentrations of chlorine are highly corrosive. Do not swallow the water. If accidentally swallowed, seek immediate medical attention.

How long should you run a filter after shocking a pool?

Run your pool pump and filter for at least 8 hours after you shock your swimming pool. This provides adequate time for the filter to clean the water and for the pump to circulate the chemicals. If you’re treating algae, plan to run the filter for ideally 24 hours.

Is it okay to shock a pool during the day?

You can shock your pool during the day if you’re using a stabilized chlorine shock that contains cyanuric acid (such as dichlor shock). The cyanuric acid will help protect the chlorine from being destroyed by the sun’s UV rays. However, do not add a shock treatment during the day if you’re using unstabilized chlorine, like calcium hypochlorite (cal-hypo) shock. This type of shock without cyanuric acid will be destroyed by the sun. Check out our guide on the Best Shock for Your Pool for more information.

Why does the pool water turn cloudy after shocking?

It’s normal to experience cloudy water after shocking your pool. This means that the algae and contaminants are dead and suspended in the water. You can use a clarifier or flocculant to clear up your water.

How long do I need to wait to swim after adding other pool chemicals?

You can usually swim within an hour after adding other chemicals to your water. But chlorine shock needs time to circulate and dissipate. For example, if you add calcium chloride to raise your calcium levels, you should wait about an hour for the filter to completely cycle the chemical in your pool. However the dissolving time of other pool chemicals, like muriatic acid or flocculant, depend on how well it was initially mixed into the water. Always retest your water before swimming to make sure your levels are back within the appropriate ranges.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post How Long to Wait to Swim After Shocking a Pool appeared first on Swim University®.

Wondering how much shock to add to your pool? The exact amount you need to add depends on the size of your pool, the type of shock your using, and whether you’re shocking as part of regular pool maintenance, or treating an issue like algae. For general pool maintenance, add one pound of shock for every 10,000 gallons of water in your pool. But if you’re experiencing algae issues, you’ll need to add more shock:

• Light Green or Teal Green Pool Water (early-stage algae): Double shock your pool with two pounds of shock per 10,000 gallons.
• Darker Green (significant algae growth): Triple shock your pool with three pounds of shock per 10,000 gallons.
• Black Green (black algae and extreme growth): Quadruple shock your pool with three pounds of shock per 10,000 gallons.

Shocking your pool with a concentrated amount of chlorine is the most effective treatment for killing algae. An algaecide, on the other hand, is more effective at preventing algae in the first place.

What is Pool Shock and What Type Should You Use?

Shocking a pool is the process of adding a highly concentrated dose of chlorine to your swimming pool water. By quickly raising the level of free chlorine in the water, the pool shock kills algae, bacteria, contaminants, and chloramines.

There are several types of pool shocks on the market and what works well for one pool may not be the best choice for another. Here are the most common types of shock and when to add them:

Cal-Hypo Shock (Calcium Hypochlorite)

Cal-hypo shock is the strongest pool chlorine shock available. It’s the best choice for a strong treatment or if you’re combating algae. But because cal-hypo contains calcium, it can cause scale buildup in a salt generator. So if you’re a saltwater pool owner, use sparingly or consider another type of shock. You’ll also need to wait at least eight hours after shocking before you swim again. And unlike regular chlorine tablets or chlorine granules, cal-hypo shock is unstabilized chlorine. That means it’ll get destroyed by the sun’s UV rays, so you’ll need to use cal-hypo shock at night.

Dichlor Shock (Sodium Dichlor)

Dichlor shock has less chlorine than cal-hypo shock, but it’s still effective. You can use it for weekly treatments or to battle algae issues. Though it won’t contribute to scale buildup, it will raise your cyanuric acid (CYA) levels. Because it contains CYA, it’s stabilized and that means you can it to your pool doing the day. But you still need to wait at least eight hours before you swim again.

Non-Chlorine Shock

Non-chlorine shock is a great option as a mild, weekly treatment. It won’t affect your calcium or cyanuric acid levels and you can swim shortly after using it. However, keep in mind that it’s not an effective way to treat severe algae problems, since it acts as an oxidizer but not a sanitizer.

Still feeling confused about water chemistry and algae problems? Check out our Pool Care Video Course for more help.

How Much Shock Should You Add to Your Pool?

In general, add one pound of shock to your pool for every 10,000 gallons of water. But if you’re experiencing an algae problem, you’ll need to add double, triple, or quadruple the amount of shock. Regardless, always follow the manufacturer’s instructions when adding pool chemicals to your water.

The goal is to achieve breakpoint chlorination, which is the level of chlorine needed to remove algae, contaminants, and chloramines from the water. In general, chlorine levels that reach 30 ppm mean you’ve reached breakpoint chlorination.

If you have high pH levels, high CYA levels, or high water temperatures, you’ll need a higher concentration of chlorine, and the shock may take longer to remove all the algae, bacteria, and contaminants in the water.

If your pool’s volume makes the math complicated when you’re calculating how much shock to add, consider rounding up to ensure your pool gets enough chlorine. And if you need help calculating how many gallons of water your pool holds, check out our pool volume calculator.

You should add shock when your chlorine levels are unbalanced and you need to refresh your sanitizer. Shocking your pool will increase your free available chlorine levels and decrease your combined chlorine levels.

• Free Available Chlorine: The amount of chlorine available to kill bacteria and contaminants. It should be between 1 to 3 ppm. This might
• Combined Chlorine (Chloramines): This is the portion of total chlorine that has reacted with the microorganisms in the water. It should be no more than 0.2 ppm.

How to Add Shock to Your Pool

There are a few steps to consider before and after shocking your pool water.

1. Test Your Pool Water

Use a water test kit or test strips to check your pool’s water chemistry. Ideally, your pool’s pH level should be balanced (between 7.4 and 7.6) before shocking to maximize the results. However, some shocks may raise your pH, so it’s okay if it’s on the lower end. Also note your CYA and Calcium Hardness levels if you’re adding shock dichlor shock (that will impact CYA) or cal-hypo shock (that will impact Calcium). The normal ranges for your water chemistry should be:

• Total Alkalinity: 100 to 150 ppm
• pH: 7.4 to 7.6
• Calcium Hardness: 180 to 220 ppm
• Cyanuric acid (CYA): 30 to 50 ppm

2. Prepare the Shock

Like all pool chemicals, always add shock to your pool water with the right protective equipment. Wear goggles, rubber gloves, and long sleeve shirt and pants to protect your skin.

The package instructions will provide guidelines for application. Some products can be added directly to your pool, while others should be mixed in a bucket of water with a wooden stick before being broadcast to your pool.

3. Add Shock to Water

Always add your shock to the deepest part of your pool first. Use a pool brush to disperse the granules to prevent them from building up in a single spot.

If you notice cloudy water, after shocking your pool, don’t panic: a cloudy pool is a sign that the algae is dead. Vacuum your pool, run your filter and consider adding a pool clarifier.

Frequently Asked Questions About Pool Shock

Need more help with adding pool shock? Here are some common questions and answers.

Can a pool be shocked too much?

Yes, it is possible to add too much shock. And if you have a smaller pool, it can take much longer for the chlorine levels to drop. Be sure to test your ph and chlorine levels afterwards and do not use the pool until the chlorine has dropped back down to 3 ppm.

How many bags of shock do I need for a 10,000-gallon pool?

This depends on the type of shock you’re using and the size of the bag. Your package directions will provide information on how much to use for your pool volume. Use more to clear up algae.

How long should you run the filter after shocking a pool?

Keep your pool filter and pool pump running for at least 6 hours after shocking your swimming pool. This provides ample time for the filter to clean the water and allows the shock a time to fully circulate within the water. If you are battling algae, run your filter after shocking for anywhere from 24 hours to a full week, depending on how much algae you have.

How long does it take pool shock to work?

Pool shock needs 12 to 24 hours to work to kill algae. Wait at least eight hours after shocking before swimming again. Test your water again 24 hours after your treatment. Once your chlorine levels are within normal range, it’s safe for swimmers again.

Should I shock my pool every week?

Yes, you should shock your pool weekly as part of regular maintenance. This helps keep contaminants out of the water and prevents algae growth from taking over. You should also shock your pool after any heavy rain, or after a pool party where you’ve had a lot of people in the water.

Does shocking a pool raise the pH levels?

Cal-hypo shock will slightly raise your pH. Non-chlorine shock will not influence your pH.

Can I use bleach or liquid chlorine to shock my pool?

Many pool owners use bleach or liquid shock in their pools. Sodium hypochlorite, a.k.a. liquid shock, is a commercial strength liquid chlorine. Containing 12.5 percent sodium hypochlorite, it’s stronger than store-bought bleach. Household bleach sold in one-gallon jugs contains 5 percent or less sodium hypochlorite. If you do use bleach to shock your pool, you’ll need to add significantly more than you would traditional pool shock to achieve higher chlorine levels.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post How Much Shock Should You Add to Your Pool appeared first on Swim University®.

If you’ve noticed that your total alkalinity is higher than it should be, it’s an easy fix. To lower the alkalinity in a pool, use either muriatic acid or sodium bisulfate (pH reducer). Here’s a quick guide explaining how alkalinity levels get too high and what you can do to lower your alkalinity in a pool.

What is Total Alkalinity?

Alkalinity acts as a buffer to your pool water’s pH, helping keep your pH levels from fluctuating drastically. So balancing your total alkalinity is important in order to maintain consistent pH levels.

Your total alkalinity should be between 100 and 150 parts per million (ppm). And your pH should be between 7.4 and 7.6. Anything much higher or lower will disrupt your water chemistry, affect your pool’s ability to sanitize, and can damage your pool equipment in the long run.

How Do Alkalinity and pH Affect Each Other?

If your total alkalinity is too low, there’s not enough of this helpful buffering chemical in the water to help stabilize your pH. When your total alkalinity is too high, the elevated alkalinity may cause your pH level to rise along with it. And that can reduce the effectiveness of the chlorine in your water.

So if your total alkalinity is in the normal range (100 to 150 ppm), your alkalinity will help stabilize your pH. And stabilized pH helps your chlorine do its job to sanitize your swimming pool.

By the way, we know pool water chemistry can be extremely confusing. So if you want a step-by-step guide on how to keep your water balanced, check out our Pool Care Video Course.

What Causes High Total Alkalinity?

Unfortunately many of the pool chemicals you add to your water can impact your total alkalinity. Similarly, low levels of chlorine and a high bather load can bring your pH and alkalinity levels up.

Cyanuric Acid

The most common chemical that raises total alkalinity is cyanuric acid (a.k.a. CYA or chlorine stabilizer). CYA is used to stabilize your chlorine and prevent it from evaporating due to the sun’s UV rays. And it also acts as a buffer to the acidity caused by chlorine.

For example, stabilized trichlor chlorine has a pH of around 3. So when you use trichlor chlorine to sanitize your water, you are making it more acidic. But because it’s stabilized, it contains cyanuric acid. And that buffers the acidity in your pool water. Buffered acidity can raise the alkalinity.

That’s why it’s so important to routinely test your pool water chemistry with test strips or a liquid test kit to ensure all of your levels remain properly balanced.

Low Sanitizer Levels

The other thing that can affect your alkalinity and pH is a high bather load in water with low chlorine. So if you have low chlorine levels and lots of swimmers in the water, they can leave behind contaminants that disrupt pH. And disrupted pH can disrupt the total alkalinity.

Pool Shock

You may also have issues with high alkalinity levels when you shock your pool. While it’s important to shock your pool on a regular basis, chlorine-based pool shocks are highly alkaline and will raise pH and therefore alkalinity. So you may notice higher pH and total alkalinity after shocking your water.

What Happens if Your Pool Alkalinity is Too High?

Since your alkalinity impacts your pH, and your pH impacts almost everything in your water, high alkalinity can cause a range of issues.

Causes High pH

If the alkalinity is too high, chances are your pH is too high. And if you have high pH, you may experience cloudy water and scaling. Plus scaling inside the pipes will restrict water flow, which puts a strain on your circulation and filtration system.

Reduces Chlorine Effectiveness

Total alkalinity levels affect your pH, which affects chlorine. And as a result, your pool’s chlorine will become less effective at sanitizing the water.

May Irritate Skin and Eyes

If the alkalinity and pH levels are off, swimmers can experience itchy skin and burning eyes. And it may also shorten the life of your bathing suit fabric and goggles.

Leads to Scale Build Up

Because high alkalinity disrupts the pH balance, it can lead to calcium buildup. And with high calcium, you may see scaling throughout your pool. You may also have visible calcium deposits collecting on the pool surface or calcium hardness buildup that you can’t see inside your pool equipment.

Creates Cloudy Water

High alkalinity can lead to calcium buildup. And high calcium levels in the water create cloudy pool water.

How to Lower Alkalinity in a Pool

There are two ways to lower total alkalinity: using muriatic acid or using a pH reducer, a.k.a. sodium bisulfate. Keep in mind that whichever method you use will also lower your pH levels. And check out our guide on how to lower pH in a pool for more information.

How to Use Muriatic Acid to Lower Alkalinity

Pool-grade muriatic acid is similar to the hydrochloric acid that’s used to clean concrete and brick, but with a lower concentration of hydrogen chloride. It can help lower total alkalinity, remove calcium deposits, and clean filters. But it’s extremely corrosive and more dangerous to handle than sodium bisulfate.

So because it’s an acid, always wear the appropriate safety equipment (including a mask to protect yourself from fumes) and follow the manufacturer’s directions on how to add the acid to your pool. Even though muriatic acid is somewhat diluted, certain brands require you to dilute it further before adding it to your pool.

1. Turn off your pool pump and wait until the water stops moving completely.
2. Calculate how much muriatic acid you need to add to your water. As a general rule, it takes 25.6 ounces of full-strength muriatic acid to reduce the alkalinity in a 10,000-gallon pool by 10 ppm.
3. Pour the muriatic acid into the deepest part of your pool and allow it to remain in the water for an hour.
4. Turn on your pool pump and let it run for at least 5 hours before testing alkalinity again.
5. After testing pool water alkalinity, retest your pH levels.

If you’re more concerned with lowering your pH than your alkalinity levels, here’s a chart to help you calculate how much muriatic acid to use.

Lowering alkalinity with muriatic acid won’t happen quickly. You may need to repeat the muriatic acid process after a few days if your levels aren’t within range. And if your alkalinity levels were literally off the charts, it can take several rounds of adding muriatic acid for your levels to appear within range.

If you need more help using muriatic acid, be sure to check out our complete guide on how to safely use muriatic acid in your pool.

How to Use Sodium Bisulfate to Lower Alkalinity

Sodium bisulfate, also known as acid salt or dry acid, is sold as pH down, pH reducer, pH minus, or pH decreaser. It works the same way as muriatic acid but it’s safer to use.

However, though this method is safer to work with, it is more expensive. And you’ll still need to store the dry acid in a dry place protected from moisture.

Keep in mind that this will lower both your alkalinity and pH together, so be sure to retest both levels afterward.

• Follow the directions on the product to calculate how much to add to your pool water.
• Fill a bucket 3/4 of the way full with water and add sodium bisulfate.
• Use a wooden stick to mix the solution until the granules have completely dissolved. Any undissolved granules may sink to the bottom of the pool and destroy its surface.
• Carefully pour the dissolved solution around the pool’s perimeter, starting with a deep end.
• Retest the alkalinity and pH of your water. If necessary, repeat the procedure.

Frequently Asked Questions About How To Lower Alkalinity in a Pool

Need more help bringing your alkalinity into range? Here are some common questions and answers.

How do I bring the alkalinity down in my pool?

You can reduce the total alkalinity in your pool with a strong acid, such as muriatic acid or sodium bisulfate (pH decreaser). Pay attention to the directions on the bottle, measuring and mixing only what you need to bring your alkalinity levels back to the ideal range of 100 to 150 ppm.

What happens if the alkalinity is too high in a pool?

When alkalinity is too high in your swimming pool, your chlorine won’t sanitize the water as effectively. And it can lead to calcium buildup, and cloudy water and irritate a swimmer’s eyes and skin.

How do you lower alkalinity without lowering pH?

Total alkalinity and pH are so closely related that it’s very challenging to lower the alkalinity without lowering pH. So adding acid to the pool will reduce the total alkalinity, but it will also reduce your pH. If you need to raise the pH after using acid, you can aerate your pool water. This will bring the pH back up without affecting the alkalinity.

Does baking soda lower alkalinity in a pool?

No, baking soda will not lower your alkalinity levels. When you add baking soda or sodium bicarbonate to your pool water, it will raise both your alkalinity and pH. Baking soda is great for pool owners to have on hand as a substitute for alkalinity increaser. And soda ash, a.k.a. sodium carbonate, is another option for raising your alkalinity and pH. But again, neither will lower high alkalinity levels.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post Alkalinity Too High? Here’s How to Lower Alkalinity in a Pool Quickly appeared first on Swim University®.

Is the pH in your pool too high? If the levels stay high for too long, you might notice itchy eyes and skin, cloudy water, algae growth, and even damaged pool parts. So you’ll need to add some pool chemicals ASAP to bring your pH back down to normal levels. There are two ways to lower pH in a pool: pH decreaser (sodium bisulfate) or muriatic acid.

For a quick chemistry refresher: pH measures whether a substance is basic or acidic. The pH scale ranges from 0 to 14, where 7 is neutral, anything that measures below 7 is acidic, and anything that measures above 7 is basic. When properly balanced, your pool’s pH needs to be between 7.4 and 7.6.

Everything that enters the pool has the potential to affect pH level – even the swimmers themselves. Things like rain, dirt, and debris in your water can also knock things out of balance. And even salt water systems generate naturally high pH levels. So because pH is so volatile, it’s important to regularly test your pool’s pH levels as part of your pool maintenance routine.

Keep reading for a complete guide on what affects your pH and how to lower pH in a pool with pH decreaser or muriatic acid.

How Do pH and Total Alkalinity Affect Each Other?

Your total alkalinity and pH levels go hand in hand. And it’s your alkalinity that helps keep your pH level stable. Without this buffer, the pH would wildly fluctuate. When your total alkalinity is too low, the pH becomes unstable. And when it’s too high, it can bring up your pH levels with it.

That’s why adjusting your alkalinity before adjusting your pH is so important: it can help bring your pH into range. Your total alkalinity should be between 100 and 150 parts per million (ppm). If you find that your total alkalinity is too low, but you have a pH higher than 6.8, use an alkalinity increaser. If your total alkalinity is too high, using a pH decreaser or pH reducer like sodium bisulfate will bring down both your alkalinity and pH.

Still feeling confused about pool chemistry? Don’t worry, you’re not alone! We created the Pool Care Video Course to help pool owners master their water chemistry once and for all. Check it out!

What Happens if Your Pool pH is Too High?

Once your pH level reaches 7.8 or higher, that’s considered high pH. And if your high pool water pH is left alone too long, can lead to a number of issues, including eroding pool parts and affecting swimmers themselves.

Reduces Chlorine Effectiveness

When the pH is too high, your pool’s chlorine won’t be able to clean the water as effectively. You’ll need to use more chlorine to get the same effect as before, which can affect the rest of your pool’s chemical balance. Without chlorine working effectively to kill microbes, you could end up with an algae bloom. And you may also end up with calcium buildup, which can lead to cloudy water and damaged pool equipment.

Irritates Eyes and Skin

High pH may cause swimmers to have itchy, red eyes. They may experience skin irritation, as well. So while many people think that high chlorine levels cause eye and skin irritation, it’s really high pH.

Erodes Swimsuits and Swimmer Gear

The high pH isn’t good for your swimsuits or goggles. Over time, the chemical imbalance may cause your swimsuit to fade, or degrade the fabric to the point where you can’t wear the suit anymore. Goggles may weaken and break sooner than you’d expect.

Damages Pool Equipment

The high pH will lead to calcium scale build-up, not just on the walls of your pool, but on your pool equipment, too. It’s possible the build-up will clog up equipment and block water flow in and out of the pool. This can introduce air into the pool pump, which will cause malfunction and may render it useless.

How to Lower pH with pH Decreaser (Sodium Bisulfate)

Most commercial pH decreasers, like pH Down or pH minus, are made with sodium bisulfate, also known as dry acid. They’re safer and less corrosive to use than muriatic acid, but they generally cost more.

Avoid adding it to your pool on a windy day, since this increases the chance the powder will blow back into your face while using it.

1. Test Your Water

Start by testing your pH and alkalinity levels so you know how much you need to lower everything. If your total alkalinity is also too high, don’t worry: the pH decreaser will lower your alkalinity as well.

2. Measure Out the pH Decreaser

Read and follow the manufacturer’s directions to figure out how much ph decreaser you need to use.

It’s okay to use less and add more later. Remember, it’s easier to add more to correct your water balance than to adjust the pool chemistry if you add too much.

3. Add the pH Decreaser to Your Pool

Pour the chemical directly into your water near the return jets and in the deepest end of your pool. Keep the pump running. Do not add it to the skimmer. If you’re a pool owner with an above ground pool, you may need to help stir the water yourself with a pool brush.

4. Let the pH Decreaser Dissolve

Allow your pool’s filtration system to circulate the chemical throughout the water and dissolve. You may want to brush away any undissolved clumps off of your pool’s surfaces, or it can damage your pool walls and pool floor.

5. Retest Pool Water, Repeat As Needed

Immediately retesting your water isn’t necessary, but make sure you complete another test within 24 hours. If your pH and total alkalinity are within the normal range, congratulations! But, if you find they’re still high, repeat the process again.

How to Lower pH with Muriatic Acid

Muriatic acid, also known as hydrochloric acid, is a highly corrosive and dangerous chemical. So if you opt for this method to lower your pH, you’ll need to take extra precautions. Cover your body completely with clothing. And wear thick gloves, safety goggles, and a mask to avoid breathing in fumes. Even though it’s not a powder, you still want to avoid a windy day because of blowback and splashback.

1. Test Your Water

Test pH and total alkalinity so you know how much you need to lower both levels. Muriatic acid will lower both pH and alkalinity together. But they may decrease at different rates.

2. Measure Out the Muriatic Acid

Calculate how much muriatic acid you need to lower your pH to the normal range. If your pH reading is above 7.8 and you have a 15,000-gallon pool, start by adding 1 quart (1/4 gallon) of muriatic acid. Then after letting the acid circulate for one hour, retest your levels. If you have a smaller pool, start by adding one cup of muriatic acid at a time. Wait for one hour, then add more as needed. Check out our chart below on how much muriatic acid to add based on your pH levels and pool size.

3. Add Muriatic Acid to your Pool Water

Because this is an acid, it can damage your pool liner if it starts to collect in one place. So always run your filter to keep your water circulating (ideally on the circulate setting). Remember, you can always add more acid later so start slowly!

It’s easier and safer to handle muriatic acid if you dilute it in a bucket of water first. The ideal ratio of water to muriatic acid is 10:1 but always follow the manufacturer’s instructions. And be sure to add the water before adding muriatic acid to avoid splashback.

• Method One: Turn off the pool’s pump and add the muriatic acid in a small, steady stream directly into the deep end of your pool. This ensures the acid will go directly to the bottom, rather than floating around at the pool surface. Then turn your pump on and let it circulate the acid through the water.
• Method Two: Slowly pour the acid into the pool near your return jets and let the pump circulate it. For above ground pools, add the acid slowly by walking around your pool so it doesn’t get concentrated in a single spot.

If you want more help safely adding muriatic acid to your pool, be sure to check out our guide.

4. Let the Muriatic Acid Dissolve

Keep your pool’s filter running (ideally on circulate) and let the chemical dissipate. It should be dissolved within an hour. But it could take longer if you’ve had to add a large dose.

5. Test Your Water Again

Test the pH and alkalinity again after an hour or two. If the levels are still high, repeat the process again, adding a little bit of muriatic acid at a time.

It should be okay to swim after one hour of pool circulation if you’ve only added a little muriatic acid. But if you’ve added a larger quantity, wait 24 hours before retesting your water and swimming.

What If the pH and Alkalinity Won’t Balance?

It’s not uncommon for either your alkalinity or pH to remain unbalanced after adding pH decreaser or muriatic acid. You could have added enough muriatic acid to bring the pH into range, but your alkalinity is still too high. Or you’ve added enough acid to bring down your total alkalinity to the proper level, but now you have low pH.

If both your pH and alkalinity levels are too low, you can add soda ash to help bring them up. But what if you only need to bring your pH into range?

You can increase your pH levels without affecting your alkalinity by using pool aeration (see our pool aeration guide for more information). Using a water fountain or pool aerator will create bubbles that help outgas carbon dioxide in the water. As carbon dioxide leaves the water, the pH will rise without impacting your total alkalinity. And if you need to bring down your alkalinity, you can add more acid while aerating your water to keep your pH levels up.

Frequently Asked Questions About How to Lower pH in a Pool

Need more help lowering the pH in your swimming pool? Here are a few common questions and answers.

How do I lower the pH in my pool naturally?

Lowering a pool’s pH naturally can be done in four ways: installing a distilled water system to pump in water, cleaning your pool on a regular basis, leaving it alone, and letting the pH level come down on its own as minerals build-up, or installing a pool heater. The heated water will be able to dissolve natural substances better than cooler water. No matter what, you still need to use test strips or a testing kit to check levels regularly and prevent them from coming down too low.

What happens if pH is too high in a pool?

When the pH is too high in your pool, your chlorine won’t sanitize the water as effectively. Swimmers may experience eye redness and irritation. Bathing suits and goggles may fade and wear faster than normal.

Can you swim in a pool with high pH?

It’s not recommended to swim in a pool with high pH. When your pool’s pH is high, the chlorine won’t work as effectively to kill bacteria. And high pH levels can irritate swimmers’ eyes and skin.

Will shocking pool lower pH?

Adding shock can actually raise your pH levels. If you use a calcium hypochlorite (cal-hypo) shock, this can raise your pH levels temporarily. So test your chemical levels regularly, especially after shocking.

Does vinegar lower pool pH?

Vinegar contains acetic acids, which are helpful for lowering pH. However, the problem with this approach is that you would need a lot (several gallons) of vinegar to address pH issues in your pool. And when used in high amounts, the vinegar will leave behind sugars and other impurities. The sugars become food for microbes present in the water, and the impurities may affect your pool’s chemistry.

Will baking soda lower pH in a pool?

Adding baking soda to your pool will actually raise the pH and alkalinity of your pool water. Baking soda, better known as sodium bicarbonate, is naturally alkaline, with a high pH of 8.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post How to Lower pH in a Pool Quickly with These Common Chemicals appeared first on Swim University®.

Which one is best: a salt water pool vs. a chlorine pool? Salt water pools tend to have gentler, smoother water than other pools. And you only need to add salt to your water once or twice a year to keep things sanitized. But you’re still technically swimming in water with chlorine. And salt water generators are expensive to buy and more complicated to maintain.

So before you switch the type of pool you have, here’s everything you need to know about salt water pools vs. chlorine pools.

How Does a Salt Water Pool Work?

A salt water pool uses a salt water generator, also known as a salt water chlorine generator. Through electrolysis, the salt water generator converts salt in your pool into chlorine.

That’s right: a salt water pool is sanitizing your water with chlorine. But instead of buying and adding chlorine tablets or granules to your water, you’re buying and adding pool-grade salt.

As that salt stays in the water, getting recycled and reused by the generator as it continues to maintain your chlorine levels. Again: this is NOT a chlorine-free alternative to a traditional chlorine pool. It’s just a different process of making chlorine.

Salt water swimming pools usually need salt levels of 3,000 ppm (parts per million) before the salt chlorine generator start working. And that’s the same amount of salinity as human tears. So salt water pool owners won’t find the water incredibly salty, like ocean water.

By the way, if you need more help with pool maintenance and making choices about your pool, be sure to check out our Pool Care Video Course!

Benefits of a Salt Water Pool vs. Chlorine Pool

Here are a few reasons why a salt water system is a great investment.

1. You add salt to your water instead of chlorine

Handling pool-grade salt is a lot safer and easier than chlorine pucks or granules. And as the salt water generator uses the salt to produce chlorine, the salt gets recycled back into the water and reused again. That means you usually only add salt at the beginning of the pool season or if a heavy rainstorm dilutes your pool water.

It also means less maintenance constantly buying, adding and adjusting your chlorine levels. And pool-grade salt is much cheaper and simpler to buy than chlorine. A salt water pool can be worth it just to never have to handle chlorine again!

2. The water is gentler and smoother

Salt water pools have smoother, silkier water. Some sensitive swimmers who are normally irritated by chlorine pools find salt water pools to be much gentler. And it tends to be less corrosive to swimsuits, too.

3. Chlorine levels stay stable

Because the salt water generator monitors and releases a slow, steady output of chlorine, the chlorine levels stay consistent. And since the chlorine levels are consistent, salt water pools can avoid problems like algae and cloudy water. Fewer drops in chlorine levels also mean fewer chloramines, which is a chlorine byproduct that causes that nasty, chlorine-like smell in pools.

Downsides of a Salt Water Pool vs. Chlorine Pool

As great as a salt water pool seems, there are a few drawbacks to a salt water pool vs. a chlorine pool, including the upfront cost and ongoing equipment maintenance.

1. It’s an expensive initial investment

It can cost several thousand dollars to convert a chlorine pool to a salt water system. That includes purchasing the salt water generator, or salt chlorine generator, and the labor to install it.

2. Maintenance is more complex and expensive

Salt water generators and the salt cells inside need to be inspected and cleaned regularly. And you’ll need to replace your salt cell every 3-7 years, which can cost another few hundred dollars. While you won’t need to constantly buy chlorine tablets or granules, you will need to use more electricity to keep your salt water generator running and producing chlorine. And if you ever need any major repair or maintenance to your system, you’ll likely need to hire a specialized professional.

3. It’s not totally hands-free

While it’s easy to get excited about never having to manually add chlorine to your water again, you’ll still need to perform regular pool maintenance checks on your water and your salt water system. This includes regularly testing your water, especially your pH. pH levels tend to drift higher in salt water pools. And pH above 7.6 can lead to skin irritation, burning eyes, and calcium build-up or scaling on your pool equipment.

Be sure to check out our guide on 9 Common Salt Water Pool Maintenance Mistakes for more help.

4. Salt water generators don’t work in colder temperatures

Salt water pool systems won’t produce chlorine if your water is 60 degrees Fahrenheit or below. So if you’re in a colder climate without a heater, your chlorine production will stop when your water temperature drops too low.

5. It can corrode pool parts

While salt water isn’t harmful in average doses, it can start to break down equipment if it starts to build up. Automatic pool covers, pool liners, metal pool equipment, and even natural stonework or landscaping near the pool can start to erode with too much salt water exposure. So keep an eye out for exposed metal components, especially on vinyl pools. But fiberglass pools are generally more safe from salt water corrosion.

Which is Better: Salt Water vs. Chlorine Pool?

Whether you have an above ground pool or an inground pool, the pros of a salt water pool are the same:

• You won’t need to constantly buy and add chlorine to your water.
• It’s gentler on your skin and eyes with a softer, silkier feel.
• Your chlorine levels will remain stable, keeping your water sanitized.

But here are the cons of a salt water pool:

• It comes with a higher initial cost and ongoing maintenance costs.
• You may experience chronically high pH levels.
• You’ll need to monitor your salt water generator
• Salt water may corrode some swimming pool fixtures

Overall, if you can afford the initial investment, the costs between salt water vs. chlorine pools even out. Given the lifespan of a salt water generator and how often you’ll need to repair or replace parts, you’ll probably spend the same as you would maintaining a chlorine pool. But it’s worth it for a better swimming experience and never having to handle a chlorine tablet again.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post Salt Water Pool vs. Chlorine Pool: Which One Is Better? appeared first on Swim University®.

Cyanuric acid, or CYA, is also known as pool conditioner or pool stabilizer. And it’s crucial for protecting your chlorine from being destroyed by the sun’s UV rays. So if your CYA levels are too low, your chlorine won’t last as long — and that leads to unsanitary pool water.

When do you know if your CYA is too low? Your pool’s cyanuric acid levels should be between 30 and 50 parts per million (PPM) and even a little higher for saltwater pools. However, indoor pool owners don’t have to worry about CYA levels, since the chlorine isn’t directly impacted by the sun’s ultraviolet rays. Cyanuric acid is only really a concern for outdoor pool owners.

In order to raise your cyanuric acid levels, you’ll need to add a pool stabilizer or pool conditioner to your water. You can also start using stabilized chlorine, like sodium dichlor or trichlor, to sanitize your pool.

If you’re wondering why these levels are low in your pool and how to bring them up, here’s everything you need to know about what causes low cyanuric acid levels and how to raise cyanuric acid in your pool.

What Causes Low Cyanuric Acid?

Chances are, your CYA level is low because you’re not using stabilized chlorine in your pool. Stabilized chlorine, like sodium dichlor or trichlor tablets and granules, already contains cyanuric acid. This helps protect it from being destroyed by the UV rays from the sun. If you’re using unstabilized chlorine, Unstabilized chlorine, like sodium hypochlorite (liquid chlorine), lithium hypochlorite, and calcium hypochlorite, does not contain cyanuric acid.

Other things like rain, splashout, and water dilution can cause a decline in your cyanuric levels as well. So if you’ve had to partially drain and refill your water recently, you will also have low CYA levels.

By the way, if you find pool maintenance confusing and you’d like more step-by-step help, check out our Pool Care Video Course.

What Happens if Cyanuric Acid Levels are Too Low?

When the level of cyanuric acid is too low in a pool, you can end up with all kinds of chlorine problems and unsanitary water issues.

Chlorine Use Increases

Sunlight naturally breaks down pool chlorine — and quickly. An entire pool’s worth could be gone within a few hours and without CYA present to protect it, you could find yourself adding more chlorine daily to keep it clean.

Chlorine Won’t Sanitize As Effectively

Because the sunlight is essentially eating your chlorine, there’s just not enough available to keep the water clean. Pollutants, bacteria, and viruses can easily take over the water.

Pool Water Can Turn Green with Algae Growth

When you’re water isn’t clean, it may become the perfect breeding ground for algae growth. And green isn’t the only color you need to worry about. Some bacteria can even lead to black algae or pink slime – and no matter what color it is – it’s unsafe for swimmers. It’s every pool owner’s nightmare.

Unbalanced Pool Water Chemistry

Your chlorine level drops if there is not enough CYA in the water to protect it. Inadequate chlorine levels can’t keep the water clean and set off a chain reaction affecting total alkalinity and pH balance.

Chlorine Smell and Chloramine Build up

With low CYA, the free chlorine gets used up faster. When the chlorine in the pool binds to pollutants like urine, sweat, and sunblock, it creates combined chlorine or chloramines. This kind of chlorine is less effective as a sanitizer and contributes to that strong chlorine smell you’ve undoubtedly experienced at public pools.

How To Raise Cyanuric Acid Levels in A Pool (2 Ways)

There are two things you can do to increase your CYA levels: add stabilized chlorine or add a pool stabilizer and conditioner (pure cyanuric acid).

Before you add anything to your pool, test your water using a liquid test kit or test strips. Then balance your pH level and total alkalinity first. This will help any chemicals you add later work more effectively.

Note: It’s much harder to lower cyanuric acid levels than it is to raise them, so don’t overdo it. You can always add more stabilized chlorine or CYA later if needed.

1. Add Stabilized Chlorine

If you purchase a form of stabilized chlorine, such as dichlor or trichlor granules or tablets, your chlorine will come with cyanuric acid. So if you’ve been using unstabilized chlorine or liquid bleach, this can be a way to introduce CYA into your water. You can buy stabilized chlorine in chlorine tablets, granular form, or liquid chlorine.

If you have chronically low cyanuric acid levels, look for tablet or granular chlorine products with cyanuric acid and consider having them on hand as part of your regular pool chemical supply.

2. Add Pure Cyanuric Acid (Pool Conditioner or Stabilizer)

If you want to control the amount of cyanuric acid in your water, you can add pure CYA directly, also known as a chlorine stabilizer or chlorine conditioner.

As a general guideline, 3 ounces of pool stabilizer will raise a 10,000-gallon pool’s CYA levels by 10 ppm. Remember that your CYA levels should be between 30 and 50 ppm. Keep in mind that because CYA lingers in the work, you usually only need to add it once or twice a year. And it’s easier to add more cyanuric acid than it is to reduce it, so take things slowly.

Finally, cyanuric acid is exactly that: an acid. So if you don’t add the pool stabilizer correctly, it could damage your pool. Vinyl pool liners are incredibly susceptible to CYA damage. And be sure to wear protective gear, like goggles and acid-resistant gloves.

How To Add Pool Stabilizer and Conditioner

Before adding any chemicals, start by testing and balancing your pool water so you know how much you need to raise your CYA levels.

Start with a 5-gallon bucket of pool water. Add the pool stabilizer or pool conditioner to the bucket of water. Do not add the water to the CYA – you don’t want splashback! Then pour all five gallons of water-CYA solution into the pool’s skimmer and run your pool pump for several hours to help it circulate. Finally, retest your pool’s chemical levels and adjust if needed. Repeat the process if you still have lower cyanuric acid levels than expected.

Be sure to add your pool stabilizer slowly. You can always add more later. But if you end up with too much cyanuric acid, you won’t need to completely drain it to balance your pool chemistry. Slowly drain a few inches of water off and refill the pool with fresh water. Keep the water above the pool pump to prevent it from taking in air and getting damaged. If you need more help reducing your CYA levels, be sure to check out our guide on How To Lower Cyanuric Acid.

Frequently Asked Questions About How to Raise Cyanuric Acid

Need more help with cyanuric acid? Here are some common questions and answers.

What do I add to my pool if the cyanuric acid is too low?

If during the course of regular pool maintenance, you find your cyanuric acid levels are too low, you can either add stabilized chlorine or pure cyanuric acid, also known as pool conditioner or pool stabilizer. Stabilized chlorine already contains cyanuric acid.

Does baking soda raise cyanuric acid?

No baking soda doesn’t increase your CYA level. It does, however, raise your pool’s total alkalinity. It won’t protect or stabilize your chlorine levels.

Does pool shock raise cyanuric acid?

Pool shock can raise your cyanuric acid levels, depending on the type you use. If you use a stabilized chlorine shock, then yes, it will raise CYA because it’s the stabilizing ingredient.

Does Clorox pool shock have cyanuric acid in it?

Cholrox does not contain any CYA in it and will not increase the CYA levels in your water if you use it. Household bleach is unstabilized chlorine and will be destroyed by the sun’s UV rays.

Will low cyanuric acid make a pool cloudy?

If you’ve got an outdoor swimming pool and have low cyanuric acid, you may experience cloudy water. This is because CYA helps to keep your chlorine levels where they should be. And without it, the chlorine depletes faster, which leads to unstanitary cloudy water.

Does a saltwater pool need cyanuric acid?

Saltwater pools need CYA, and manufacturers recommend keeping it on the slightly higher side: between 60 and 80 PPM. In saltwater pools, you don’t add chlorine directly. Instead, you add salt, and the salt generator creates sodium hypochlorite, which also degrades under sunlight. Salt chlorine generator manufacturers recommend running with higher free chlorine levels, since the generators continuously create chlorine, it’s crucial to protect the existing chlorine.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a downloadable guide with everything you need to know about pool maintenance.

The post CYA Levels Low? Here’s How To Raise Cyanuric Acid in a Pool appeared first on Swim University®.