How To Fix Low Cyanuric Acid In A Pool

A functional swimming pool has to be maintained regularly. The chemical constituents like the pH, chlorine, muriatic acid, total dissolved solids (TDS), alkalinity, cyanuric acid, and others have to be checked to confirm if they are available in the required quantities.

Cyanuric acid is an important entity, usually added alongside chlorine. It has adverse effects if in low or high quantity. If you observe that your pool has low cyanuric acid, either by testing or intuition, be rest assured. It’s easy to fix low cyanuric acid in the pool.

How To Fix Low Cyanuric Acid In A Pool

Wondering how you can fix low cyanuric levels in a swimming pool? Let us get your answers. 

With chlorine stabilizers, your swimming pool’s cyanuric acid level will rise. Before this, you have to know about the size of your pool and the amount of cyanuric acid to add. You also need to have confirmed if the pool truly needs cyanuric acid addition or not. If it is in large quantity in the water, swimmers are at risk.


Contribution Of Cyanuric Acid To The Swimming Pool

Cyanuric acid or cyanurate serves as a protector of chlorine content in the pool. Chlorine kills germs and pathogens, helps to stabilize the color of the pool, and contributes to the pH. You cannot overrule the work of chlorine. But exposure to sunlight reduces it at a high rate. That’s where cyanurate acid comes in.

It’s a stabilizer targeted at limiting the photodecomposition of available chlorine in a swimming pool. It is also called the pool conditioner. Cyanurate acid makes chlorine last longer, which in return, serves the roles mentioned above more efficiently. Put in mind that sunlight can reduce chlorine content in swimming by 72% – 90% in hours. Cyanurate acid must be employed to form a protective shield within the chemical constituents.


Test for cyanuric acid

Before adding cyanurate acid, the level of its content in a swimming pool should be calculated. This will reveal how much is needed, or perhaps, there’s no need. The maximum level of cyanurate acid varies according to region. There are more requirements in areas where there’s regular exposure to sunlight. The average level should be between 30 ppm and 50 ppm.

1. Test strip: Visit any of your local pool stores and purchase a pack of cyanuric acid testing strips. This is the cheapest and the fastest testing method. Read through the manufacturer’s guide for precautions and instructions. Take a strip and lower it into the pool for 30 seconds. The strip will react with the water, and another color will emerge. Take the strip and compare the color with the ones on the testing strip kit. Put down your readings and proceed to other steps.

2. Turbidity tests: This test kit contains a plastic vessel, a glass test tube, and packets of chemical reagents. It’s crucial to learn how to get samples from a swimming pool. Dip the plastic vessel into the water upside down. Turn it upright when the water reaches your elbow and take your sample. There will be instructions on how to proceed with the use of the test kit.


Effects Of Low Cyanuric Acid In A Swimming Pool

1. Quick reduction in chlorine level: Free chlorine available in a swimming pool should be around 2 ppm to 4 ppm. Low cyanuric acid will expose chlorine to decompose faster. The chlorine content will be below the minimum level at every testing session since the sunlight now has more freedom to wipe it off.

2. Presence of algae bloom: In the absence of chlorine after it has been decomposed, this will provide a favorable condition for algae to develop. There might be an outburst of algae, and the water will appear cloudy. If left alone without adequate care, the water will seem disgusting.

3. Imbalance pH: A low cyanuric acid will affect the pH state. Cyanurate is a titratable alkaline substance contributing to the total alkalinity present. Now, the alkalinity and chlorine levels will reduce. The total dissolved solids (TDS) level will change too.

4. Manifestation of germs, bather, fungi, bacteria, and viruses: When chlorine is open or exposed to air, its disinfectant will reduce. This provides breeding space for germs, fungi, bacteria, viruses, pathogens, and other microbes. It will be unsafe to swim in a pool with low cyanuric acid.


How To Treat Low Cyanuric Acid In A Swimming Pool

After confirming that you truly need to add cyanuric acid to your pool, record the amount present in the water. To raise the cyanuric acid of a swimming pool, you will need the following:

1. Cyanuric acid: You can get this in a local pool store or order online. Ask for recommendations before the purchase and check for consumers’ reviews for the product chosen.

2. Protective clothing: Get comfortable long sleeves and protective shoes. If you have factory wear, take it on.

3. Safety goggles and gloves: Cyanuric acid exhibits the same toxicity as general acids. You will need safety glasses to protect your eyes and acid-resistant gloves. The safety goggles are optional, provided you will be careful to avoid splashes.

4. A bucket: To mix the cyanuric acid, there will be a need for a 5-gallon bucket or anyone with visible measurement lines.

5. Warm water: It doesn’t have to be too warm—just mild warm water. I recommend one you can dip your hands into without getting hurt. Hot water reacts with acid readily and violently as the reaction is fastened.

Not all cyanuric acid products will require you to mix the substance with water before application. But adding acid directly to a skimmer might damage it. Stay glued to your product’s manufacturer’s instructions.



  • Put on protective clothing, safety goggles, and acid-resistant gloves.
  • Pour the warm water into the bucket. Stop when the water reaches almost half of the water.
  • Open your cyanuric acid packet and calculate the required amount in the water. The rule of thumb is that 13 ounces of cyanuric acid will raise a 10000-gallon pool by 10 ppm. Put in mind that the required cyanuric acid is between 30 ppm and 50 ppm.
  • Make sure you add the chemical to the water rather than add water to the acid.
  • Mix the combination till the solution appears uniform.
  • Pour the content into the skimmer.
  • Turn on the pump. This is to aid the circulation of cyanuric acid.
  • Turn off the pump after 2 hours.


Final Thoughts

Check your cyanuric acid level once a week. Be wary of the products you add to your swimming pool. Most chlorine products have CYA in them. That should be enough to maintain the required level unless external influences intervene. Cyanuric acid additions are usually twice a year on average.

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