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.

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