Here’s How To Lower The Cyanuric Acid Level In Your Pool (FAST)


In today’s post you’re going to learn how to lower cyanuric acid (CYA) in your pool FAST.

Here’s the thing:

When your cyanuric acid (aka pool stabilizer) levels are correct, it’s a beautiful thing, maintaining and stabilizing your chlorine levels the way it should be.

But when your cyanuric levels get too high, it can cause trouble, basically rendering your chlorine useless. 

In this guide, you’ll find out the optimal CYA levels, how to properly test for CYA, and of course how to lower your CYA levels in your swimming pool when you need to …

Plus a whole lot more.

Let’s dive in!

What is cyanuric acid?


Cyanuric acid is a chemical essential to keeping chlorine working the way it should to clean and sanitize your pool.

You can buy it by itself or as an additive that can be dropped into chlorine tablets.

The best thing about cyanuric acid is that it has little effect on alkalinity, calcium hardness or pH levels. So while it works to make your chlorine more effective, you don’t have to worry about it throwing anything off. 

The reason it’s often called a pool conditioner is that it essentially weakens the strength of chlorine a bit, making it less abrasive on swimmers and objects in the pool. 

Read: A Beginner’s Guide to Pool Chemistry

But it bonds with chlorine to protect it from being broken down by the sun and makes it more effective on bacteria and algae. 

Why does your pool need cyanuric acid?

Because cyanuric acid stabilizes the chlorine molecules and keeps it from breaking down in the sunlight, it’s essential for anyone with an outdoor pool.

It’s such a popular product because it maintains chlorine levels effectively and reduces the amount of time you have to spend maintaining proper levels in your pool. In other words, instead of daily chlorine testing and balancing, you will most likely only need to do it weekly. 

It also makes algae outbreaks much less frequent since it keeps your chlorine working longer. 

Read: The Ultimate Guide to Getting Rid of Pool Algae

Note that an indoor pool will rarely need the chemical unless you have a very open area or lots of windows around the pool.

What levels of cyanuric acid are optimal?

Even a small amount of cyanuric acid is good for your pool, so if you’re afraid of going overboard, you can opt for adding trace amounts.

But the optimum level is considered 30-50 ppm (parts per million).

Any higher and it will keep the chlorine from being killed by the sun, but it will lose virtually all effectiveness in killing bacteria.

Why too much cyanuric acid is a bad thing

When cyanuric acid levels get too high, it can cause something referred to as chlorine lock, which basically means your chlorine has been rendered useless.

You’ll know it has happened when your chlorine test shows very or little chlorine even right after you’ve added it to the pool.  

When your chlorine isn’t working, bacteria and algae are not being treated!

How to test for cyanuric acid levels


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Any time you test your other chemical levels, it’s a good idea to also test your cyanuric acid levels.

If you’re starting to notice a strong chlorine smell, sometimes that can be a sign of chlorine lock, or too much cyanuric acid in your pool. That is, as long as you have ruled out the possibility of there being a chlorine overload.

Some of the more advanced test kits come with a way to test your water chemistry, or you can simply buy test strips just for that. 

If you’re using a kit, it will usually require you to drop a chemical into a water sample from you pool to give you a reading, or you can also take it to your local pool store.

Either way, you’ll then make a determination of whether to raise, lower or leave your cyanuric acid levels alone.

How to lower cyanuric acid levels

When your cyanuric levels are too high, you have three options:

For diluting, you don’t have to use an exact science, but basically, if your cyanuric acid level is 5% too high, then you need to remove about 5% of the pool water. 

Dilution is always the best solution, but if the cyanuric acid levels are extremely high, it will be much easier to purchase a cyanuric acid reducer to bring it down, then top off with fresh water.

How to raise cyanuric acid levels

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Low cyanuric acid levels are not usually too much of a problem since even trace amounts can increase the life of your chlorine.

However, for a pool owner to keep it at the correct levels to work properly, you can simply add some cyanuric acid granules according to the manufacturer’s instructions.

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Since the most common form of cyanuric acid is usually as an additive to chlorine tablets, adding it straight to the pool like this is considered a “booster.”

Cyanuric acid vs muriatic acid

Although these two seem to get confused for each other some, they are two very different chemicals.

As we’ve explained, cyanuric acid acts as sort of a sunscreen for chlorine, while muriatic acid is used to lower a pool’s pH level.

 Both products help to manage chlorine’s efficiency but are used for very different reasons. 

Bottom line

While cyanuric acid is an essential product in keeping chlorine active longer, it’s also important to realize that too much of it will weaken it, making it less effective in killing off the bad stuff.

If you will keep your free chlorine and cyanuric acid levels balanced, you won’t have to fight algae or bacteria in any climate condition. That makes it something worth considering!

Using pool chemicals doesn’t have to be intimidating.

Just arm yourself with a little knowledge and when in doubt, remember less is more!

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