How to Test and Balance Your Pool Chemicals

How do you actually test and balance your water? And what about other levels, like cyanuric acid or calcium hardness? Knowing what to test and when can save you from big pool problems in the future.

Creators & Guests

Host

Matt Giovanisci

Founder of SwimUniversity.com

What is Pool School?

A podcast for pool owners covering pool maintenance and water chemistry.

Matt Giovanisci: 00:00

Everyone. And welcome to Pool School by Swim University, where we help you keep your pool clean and clear all year. My name is Matt, the founder of swimuniversity.com. And on this episode, we're talking about how to test and balance your pool chemicals. Let's dive in.

Matt Giovanisci: 00:26

Real quick, if you want more help taking care of your pool, be sure to grab our free pool care cheat sheet at swimu.com/cheat sheet. Now did you know that you should be adjusting your pH and chlorine in your pool at least once a week? Yes. These levels fluctuate the most in your water. And when they're off, it can lead to algae growth, eye irritation, and even damage your pool equipment and plumbing.

Matt Giovanisci: 00:50

But how do you actually test and balance your water? And what about the other levels like cyanuric acid or calcium hardness? Knowing what to test and when can save you from big pool problems in the future. So we're gonna go over a quick guide on how to test and balance your pool chemicals. Now before you can balance your chemicals, you'll need to test.

Matt Giovanisci: 01:10

So you can use test strips or a liquid test kit. You can also buy a digital reader if you're having trouble reading the colors on the test strips or the liquid test kit. Now test strips are easy to use and cheap, making them an easy option for weekly maintenance. It's the one that I prefer. Most test strips measure basics like pH, alkalinity, and chlorine.

Matt Giovanisci: 01:32

And you can get specialty test strips that measure copper, iron and even salt. Collecting a good water sample from your pool is important for getting the best results. So you wanna use a clean cup, hold it upside down so that the opening is facing the pool floor. You insert the cup into the water elbow deep, and then you turn it right side up to collect the sample. Just don't take your sample near your skimmer opening or any of your return jets.

Matt Giovanisci: 02:01

And then what you can do is dip a test strip into the water, in and out. And then hold it still in the air for about 15 seconds and compare the strip to the guide on the back of the bottle or on the packaging. You'll wanna test the pool water at least once a week and more often if you're getting a lot of if your pool's getting a lot of use, maybe if it's rained a lot, or you've just added fresh water, or you've just added chemicals. And now that you've got your results, here's how to read them. So most levels are measured in PPM, which stands for parts per million.

Matt Giovanisci: 02:35

And each test strip brand may be slightly different, but here's what you'll find on a standard six way test strip from top to bottom. So number 1 is total hardness. Your total hardness measures the amount of calcium in the water. And this level affects your pool equipment and your surfaces over time. Your total hardness should be between a 175 and 275 parts per million.

Matt Giovanisci: 03:00

It's a wide range. Alright? Number 2 is total chlorine or you might see total bromine if you have an indoor pool if you're using bromine. Your total chlorine is the amount of free chlorine and combined chlorine in the water. Now your total chlorine should be around 3 parts per million and as close to your free chlorine reading as possible, which leads us to number 3, your free chlorine.

Matt Giovanisci: 03:26

Now your free chlorine measures the amount of chlorine that's available to actively sanitize your pool water. Your free chlorine should be between 1 and 3 parts per million with 3 parts per million really being ideal. Now, your total chlorine levels or your total chlorine level minus your free chlorine level gives you what's called combined chlorine. And that's the chlorine that's been used up in the water. And it should be as close to 0 as possible, definitely less than 0.5 parts per million.

Matt Giovanisci: 04:03

But here's the thing, when your combined chlorine levels are high, it means your chlorine isn't as active and you may notice a chlorine like smell in the water, like that bleachy, summery smell. Alright? Number 4 is pH. Your pH measures how acidic or basic your pool water is. So if your pH is off, it can damage your pool equipment, it can irritate your eyes and your skin, and it stops your chlorine from working effectively, even your bromine too.

Matt Giovanisci: 04:33

Your pH should be between 7.47.6, and you can go as low as 7.2 and about as high as 7.8, just to give you a little bit of a wider range. Number 5 is total alkalinity, which helps prevent your pH from fluctuating. Your alkalinity should be between 80 a 120 parts per million. But we recommend keeping it a bit higher than 80 since having it in the water helps to keep your pH in range. And number 6 is cyanuric acid, also known as CYA or chlorine stabilizer or pool stabilizer.

Matt Giovanisci: 05:11

It goes by many names. Cyanaric acid helps stabilize your chlorine and protect it from destroys by being destroyed by the sun's UV rays. Because without that, without cyanuric acid in the water, your chlorine levels in an outdoor pool will just quickly drop. The sun burns off 1 part per million every hour. Your cyanuric acid level should be between 30 and 50 parts per million.

Matt Giovanisci: 05:38

Alright? So you've got your test results. Now what kind of chemicals do you need to add? You wanna have these chemicals on hand to balance your levels. You wanna have alkalinity increaser, or you can use baking soda, pH increaser, or you can use what's called soda ash, pH decreaser, or you can use a liquid version, which is muriatic acid, although I prefer the dry acid version of pH Decreaser.

Matt Giovanisci: 06:05

You have you need chlorine. Now that the you can use tablets, granules, or like, you know, some people it's like powder, but they're actually like little tiny balls. Or you can use liquid chlorine. You also need chlorine stabilizer, or pool stabilizer, or cyanuric acid, whatever whatever you can find by those names. Stabilizer is the keyword.

Matt Giovanisci: 06:27

You want calcium hardness increaser, which is calcium chloride. And you want pool shock, both ideally, both non chlorine and chlorine shock, like calcium hypochlorite shock. And of course, since we're dealing with pool chemicals, you wanna get protective gear like chemical resistant gloves and goggles. And not the pool goggles that you swim with. Just safety goggles.

Matt Giovanisci: 06:54

Alright. Now depending on your water and what type of chlorine you use, you might also need a metal sequestrant if you have high metals in your water like copper or iron. Alright. So let's start adding the chemicals. Now when you're adding chemicals, you wanna add them slowly.

Matt Giovanisci: 07:09

You can always add more later. Alright? So be sure that the pump and filter are running while adding chemicals. And it can either the your filter system, if you have a multipore valve, can either be on recirculate, which basically just spins the water and bypasses the filter, or just your standard filter setting. Now be sure to wait at least 20 minutes after adding each chemical to let it circulate and dissipate.

Matt Giovanisci: 07:33

And don't ever mix chemicals together outside of the pool because it can cause a toxic gas and it can even cause an explosion. I've seen it happen. Finally, here's how to order or here's the order well, how to order, you go online. You order your chemicals. Finally, here's the correct order to add the chemicals to the water.

Matt Giovanisci: 07:55

Because if you add chemicals in the wrong sequence, it can actually cause issues like cloudy water. So your chemicals and, you know, and it won't work as well. So you follow the sequence with the best results. And if you're using a metal sequestrant, do that before you add anything else. Alright?

Matt Giovanisci: 08:09

First, you're gonna adjust your total alkalinity. Like I said, alkalinity helps prevent fluctuations with pH. So adjusting your alkalinity first can help bring your pH into range. And if you need to raise your alkalinity, you can also use an alkalinity increaser or you can use baking soda. Just make sure if you're gonna buy baking soda that it is pure baking soda, sodium bicarbonate.

Matt Giovanisci: 08:31

K? If you need to lower your alkalinity, in this case, you're actually gonna use pH Decreaser or if you want a liquid version, that's muriatic acid. Now keep in mind that anything you add to adjust your alkalinity is also gonna affect your pH. And that leads us to adjusting your pH. Adjusting your pH will help your chlorine to work more effectively later, so it's important to adjust it beforehand.

Matt Giovanisci: 08:58

Alright? You can lower the pH with pH Decreaser and muriatic acid. But to raise pH, you actually can use a pH increaser or what's called soda ash. You can also use borate or borax. These are found in the laundry aisles in your in your grocery store.

Matt Giovanisci: 09:16

Now, it can be tricky to get the right balance of alkalinity and pH. So just make sure that you adjust your alkalinity first and then adjust your pH if you even need to. You may not even need to. Now after adjusting those 2, you wanna adjust your chlorine. You wanna add your chlorine tablets, your granules, or liquid chlorine directly to the water.

Matt Giovanisci: 09:36

Now keep in mind that it may take several hours for your levels to come into range if you're using tablets. And if you have a saltwater pool, just make sure that you have enough salt in the water to keep your chlorine levels in range and your saltwater generator working. Next, you're gonna adjust your cyanuric acid with a chlorine stabilizer if you need to. If you use dichlor granules or trichlor tablets, alright, and you wanna check the, active ingredients here, They may already contain cyanuric acid, and it means that you really don't have to add any stabilizers throughout the year. Alright?

Matt Giovanisci: 10:15

You may have to add it at the beginning of the year if your CYA is at 0. But once you get it into range, even at the lower range of 30 parts per million, if you're using tablets or or granules that have cyanuric acid in them, then it'll just keep those levels in range. Alright? But if you use liquid chlorine or you have a saltwater pool, well, then you need to add stabilizer to help the chlorine from being broken down by the UV rays of the sun. And if you have an indoor pool, you don't need to worry about it.

Matt Giovanisci: 10:47

Alright? Or if your pool isn't in direct sunlight. Finally, you wanna adjust your calcium hardness levels. Now these levels do more damage in the long run like eroding parts in your pool. So you don't need to adjust your calcium harness right away before swimming.

Matt Giovanisci: 11:04

And if you drain and refill your pool each year, you don't need to worry about these levels. It's for having pool water in the pool for long periods of time. You know, like many, many years. Add a calcium hardness if your levels are too too low. But But if your levels are too high, unfortunately, the only way to bring them down is by partially draining and refilling your pool with fresh water.

Matt Giovanisci: 11:26

The last chemical on our list is shock. And shocking your water is a great way to keep your chlorine active in the water and kill any extra contaminants. Non chlorine shock, aka oxidizer, helps revitalize your free chlorine and break up any combined chlorine in the water. Chlorine shock, like calcium hypochlorite or we call it cal hypo or dichlor shock, is more powerful because it has chlorine in it, and it actively kills contaminants. It's it's a better option for problem solving larger issues, like if you have cloudy water or green water or or black algae or mustard algae or any of those problems.

Matt Giovanisci: 12:08

Adding non chlorine shock once a week or part of a regular maintenance is a simple way to keep your free, total, and combined chlorine levels in check. And the the good part is with non chlorine shock, you only have to wait 15 to 20 minutes after adding it before you can swim again. On the other hand, use chlorine shock if you've had lots of swimmers, if it's if you just had a really heavy rain, to clear up cloudy water, or to kill algae. Now just be sure to balance your pH before shocking to help your shock work more effectively. And shock can change your chlorine and pH levels, so you wanna test right after shocking.

Matt Giovanisci: 12:45

And that's it. If you need more help with pool care, grab our free pool care cheat sheet at swimuniversity.com/cheat sheet. And if you found this video helpful or you found this podcast helpful, you wanna subscribe to our podcast on your favorite podcasting app for more pool maintenance tips. And when you do, you can leave us a review because that helps more pool owners just like you find this show and learn. That's it.

Matt Giovanisci: 13:11

Thanks again and happy swimming.