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Watch out with your Stabilizer; the Good and the Bad

Hello there!

Many of my customers use chlorine tabs as main sanitizer, I shared with them this information since I believe is important they know what entails to use tabs as well as any other chemical in their pool. Here you can find important information regarding Cyanuric Acid, a chemical known as Stabilizer or Conditioner.

Stabilized chlorines dichlor and trichlor (commonly known as #tabs) have about 50-58% of Cyanuric Acid in their formulas.

Cyanuric Acid (CYA), also called stabilizer or conditioner, protects chlorine from sunlight. The Sun’s ultraviolet rays degrade chlorine very quickly, creating a problem for outdoor pools. A chlorine stabilizer is needed, otherwise you will be using (and losing) chlorine all day, every day.

You might think that Cyanuric Acid is a great thing, right? Of course, it is! But there are problems that occur when we use too much of it.

Problems with Cyanuric Acid:

The problem starts when overstabilization occurs. When water evaporates, CYA stays behind and stays in the water for a long time. This can be a problem down the road because the CYA will accumulate.

As an example, 1 pound of trichlor (two 3 inch tab) in a 10,000-gallon pool will raise the CYA level by 6 ppm. With the ideal range for pool CYA being 30 ppm to 50 ppm, it’s easy to see how this level can quickly spike.

Weaker, Slower Chlorine

Since chlorine is the front-line defense against germs and diseases in water, weakening it is a bad idea.

There is approximately a 7.5% chlorine reduction factor with cyanuric acid against algae. Let’s put this formula into the real world:

If you have 100ppm CYA, your new minimum to stay ahead of algae growth is approximately 7.5ppm chlorine. Can you sustain that? It’s not practical for most pool operators, it’s expensive and especially since the EPA maximum is 4 ppm free chlorine.

With compromised chlorine you’ll soon start seeing issues like algae and cloudy water.

In summary, the higher the CYA, the weaker the chlorine, and it’s almost at an exponential rate.

Health issues

High CYA can impact your health, as a dangerous organism known as cryptosporidium parvum won’t be properly removed from the water. It can infect a swimmer’s gastrointestinal tract, causing digestive issues and diarrhea.

How to lower Cyanuric Acid levels

Method #1: Drain or Dilute your water

The most effective and economical way to lower CYA is to partially drain and dilute the pool with fresh water. There are risks with hydrostatic pressure when fully draining a pool but swapping out water can be done incrementally in the form of partial drains.

If your CYA levels are 10% too high, you’ll want to remove and replace about 10% of your pool water.

Be aware that cyanuric acid can hang around in your filtration system and pool surface. So, if you have extremely high levels of CYA, you might also need to replace your cartridge filter, backwash often or even drain, and acid wash your pool walls and floor.

Method #2: Use a Cyanuric Acid Reducer

A product such as Bio-Active or Natural Chemistry (prices around $50) is a CYA reducer that will help lower cyanuric acid in your pool. In cases where the CYA level is extremely high, you can use CYA reducer to bring it down, and then use the dilution method to top it off.

Cyanuric acid reducers are biologically based, so they work slowly. It can take a week or more to reduce your CYA levels, and many customers have reported seeing no results.

If you would like to learn more about Cyanuric Acid, you can follow the links below. This chemical has been in the market for over 50 years but in the past few years more studies have shown the high impact in Chlorine and how to maintain proper levels.


Orenda Technologies:

Swim University:

Taylor Technologies:

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