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High Levels of CYA Can Cause Algae Growth

When it comes to keeping your pool sanitized, clear and blue, chlorine is the most important chemical that you will use in your swimming pool. Whereas, Cyanuric Acid (CYA), also known as conditioner/stabilizer, helps prevent chlorine loss in swimming pools. As much as this chemical is vital in your swimming pool, it can also be extremely challenging when the levels get too high! During the hot summer months the sun’s ultraviolet rays destroy free chlorine but having the proper amount of CYA in the swimming pool can prevent that and we hope that this post helps explain why CYA is necessary for your swimming pool and how to lower it when the levels get higher than normal recommended amounts.

Typically, the ideal amount of CYA in your pool is between 30 and 50 parts per million (ppm). If your swimming pool gets more direct sunlight, that number might need to be a little higher. If you own a salt chlorinator please refer to the owner’s manual as each system has different CYA requirements. But, what happens when the number gets much higher than 100ppm and why does this happen? When CYA levels rise above 100ppm, it can cause a fair amount of problems. It can actually “bind” up the chlorine and reduce its effectiveness thus making it harder to kill algae and other bacteria in your swimming pool. The most common reason why CYA increases is because stabilizer is one of the main ingredients in chlorine tabs. Tabs are typically way overused and cause CYA to rapidly rise. When this happens you can do numerous backwashes in your swimming pool if you have a sand filter or DE filter but that can be extremely time consuming and also a huge waste of water. Another option, which we highly recommend is using our Reverse Osmosis (RO) mobile filtration system (Puripool) to recycle your swimming pool water instead of draining it.

Just this past week we processed a swimming pool that was dealing with high levels of CYA and algae blooms. The following was the initial chemistry:

Calcium Hardness – 700ppm

Total Dissolved Solids – 3000ppm

CYA – 200ppm

After filtering this 17,000-gallon swimming pool we were able to lower their water chemistry to the following:

Calcium Hardness – 120ppm

Total Dissolved Solids – 520ppm

CYA – 0ppm

In conclusion, if you maintain proper CYA levels, it can reduce the cost of operating your pool because it prevents chlorine loss and reduces the amount of chlorine needed to properly sanitize your swimming pool. Remember to always check the water chemistry in your swimming pool for adequate levels of chlorine, pH, CYA and Calcium Hardness too. It is vital that all of these levels are within normal ranges to prevent algae growth in your swimming pool.

If you’re interested in learning more about how our mobile filtration trailer can help you, contact us today and you can switch from using tabs to liquid chlorine we would highly recommend that!