Cyanuric Acid Effects As A Stabilizer For Swimming Pools

Cyanuric acid - What is it exactly? It is a pool chemical that forms a temporary bond with your swimming pool chlorine. It works to protect your pool's free chlorine from being destroyed by the natural UV rays of the sun. This pool chemical is a necessary ingredient to your water chemistry if you are using unstabilized chlorine as a water sanitizer or disinfectant in your pools.

Without it your free chlorine residual will be lost in less than two hours- this is because chlorine is very susceptible to the ultraviolet rays of the sun.

As result of this process, your chlorine residual can drop well below the recommended level for swimming pools.

This creates an extremely dangerous environment for pool bathers because diseases can be transmitted very easily between individuals. When cyanuric acid is present in your swimming pool water in sufficient amount - the free chlorine residuals will remain in the water much longer. This could be up to three to ten times longer than if cyanuric acid (CyA) were not present.

In case you are wondering - cyanuric acid does not have any disinfecting properties. Therefore, it cannot be used as a swimming pool or spa sanitizer. CyA is a pool chemical that can only be used as a stabilizer for pool chlorine. It is not a stabilizer for bromine either.

If you use the CyA conditioner or stabilizer in your swimming pools, it must be maintained between 30 to 50 ppm. This is the recommended level that will cause your swimming pool chlorine residual to have optimum effect in your pool water. Thus, giving your pool chlorine optimum protection from the sun's ultraviolet light.

When Should You Use Cyanuric Acid?

Cyanuric acid is added to your pool water as needed. This is normally when it is exceedingly difficult for you to get or maintain a free chlorine residual of 2 - 3 ppm in your swimming pools. You should perform a cyanuric acid test (CyA test) at least once a month; however, if you are using stabilized chlorine to treat your pool water, then you will need to do a cyanuric acid test every week.

When Should You Add Cyanuric To Your Swimming Pool?

When you are adding Cyanuric Acid to your pool, it will require regular testing of this chemical as I mentioned earlier. The reason for this is that we do not want the level of this pool stabilizing chemical to reach its maximum in your pool water. Because if it does, it will render your pool chlorine ineffective.

Now there are a couple of ways that you can add this chlorine stabilizer to your pool water! One way is to have the pool chlorine stabilizer suspended in perforated plastic container and add it to the pool. Another way is to dump it into a surge or atmospheric tank. This allows for the dissolution of the chemical without you having to close your pool facility.

Cyanuric acid can also be added directly to the swimming pool but doing this may delay the opening of your pool.

If you manage or run a big commercial pool at a resort or water park, you do not want to have delays.

This is a noticeably big deal when it comes to blowing away your guests and keeping them happy.

If you broadcast Cyanuric acid (CyA) directly in your pool, opening delays are caused by the sight of the pool chemical at the bottom of your swimming pool.

You see - depending on the size of the granules of the cyanuric acid, it can take as long as 48 hours for it to be completely dissolved into full solution. For this reason, using a surge or atmospheric tank is the best option to use.

Lowering Cyanuric Acid In Swimming Pools

It is a known fact that if you are using cyanuric acid (CyA) in your swimming pools, you do not get rid of it. This is another reason you should constantly test its level and maintain it between 30 and 50 ppm. You see, as you add this chlorine stabilizer to the water of your swimming pool, it increases over time.

Keep in mind that the recommended maximum ppm level of this pool chlorine stabilizer in swimming pools is 100.

Once it gets too high, you will have to get rid of or lower it immediately. The question is how? There is no known pool chemical that will lower or eliminate it. The only way to get rid of the cyanuric acid in a swimming pool is to drain your pool partially or completely.

In most cases it is best to drain the pool completely and re-balance your pool water chemistry over. When you refill your pool, you will have to begin adding CyA once again. This is only necessary if you are indeed using unstabilized chlorine as your main source of chlorine disinfectant.

Again, elevated levels of Cyanuric Acid (CyA) are not good because it can also lead to an increased risk of algae growth. It also reduces the effectiveness of your pool chlorine at extremely elevated levels. This is because at very higher levels, the amount of time required to kill bacteria in the water is increased. This is not a healthy pool environment for your pool swimmers.

Besides health-related problems, other swimming pool problems such as increased cloudiness (cloudy pool water) and high combined chlorine levels can occur as well.

Where Not To Use Cyanuric Acid

This chlorine stabilizer should not be used in water of indoor pools. Remember that CyA is used to reduce or limit the loss of free chlorine caused by sunlight; therefore, using it in the water of an indoor pool has zero benefit. You should also not use any other pool chlorine such as Trichlor or Dichlor which already contains Cyanuric acid in them CyA either.

How Much Cyanuric Acid Is Too Much?

As I mentioned earlier, when the Cyanuric acid CyA level in your pool reaches 100 ppm - it must be lowered. This is the max level that was set by The Nebraska Swimming Pool Act. And according to a study done by The Center for Disease Control (CDC), CyA significantly reduces chlorine's ability to inactivate Cryptosporidium.

And as we know, this disease is very resistive to swimming pool chlorine - so just imagine how rampant it will be in a pool that has no free chlorine disinfectant present to combat it.

Because of the findings of this study done by the CDC, the Lincoln Lancaster County Health Department recommends that swimming pools should not exceed a level of 30 ppm when using cyanuric acid.

Cyanuric acid is a pool chemical used as a chlorine stabilizer.

Swimming pool care home page.

Back To The Top