Although not often (these days) that we get many questions pertaining to pool water, this one question does tend to get asked at least five or six times a year: “What does cyanuric acid do for pool water?”

Honestly, cyanuric acid does more for the chlorine in your pool water than it does the pool water itself. As an element in water chlorine LOVES to more or less run wild and leave the water first chance it gets if not controlled (stabilized) by a compound like cyanuric acid.

In the absence of a chlorine stabilizing compound things like sunlight, wind and just plain chlorine’s tendency to ‘off gas’ would make it extremely difficult to maintain a free chlorine residual in pool water. Without a free chlorine residual pool water can easily turn green with algae, become cloudy and most CERTAINLY become a breeding ground for water dwelling bacteria and other pathogens.

Two forms of cyanuric acid?

Back in the day you could only get cyanuric acid as granules that you had to mix in a pail to form a slurry and pour down the skimmer (slowly!) with the pool pump running.

Now, however, you can purchase cyanuric acid as a concentrated liquid… which we can ASSURE you saves a lot of time!

Anyone who has ever had to mix, swirl, pour, mix, swirl, pour, mix, swirl, pour, etc., etc., etc., over and over again for a large pool will know EXACTLY what we mean by that last statement. Pouring too much of the cyanuric acid granules into the skimmer too quickly could result in dangerously high levels of pressure in the filter.

Ever see the things that can grow in stagnant water? Ever SMELL the things that grow in stagnant water? We assure you those things neither look nor smell pretty. Now picture that same water in your swimming pool or spa. Again, not a pretty thought.

Pool water that does not get ‘turned over’ properly and circulated through the filtration system will eventually become stagnant. That means Little Tony’s urine, bile, spit, or worse will never get removed from the water… which means you get to swim in it over and over again. Yuck.

“What about the chemicals? Don’t those keep the water safe?” — Not without proper circulation, no. You will wind up with concentrated pockets of the chemicals in some parts of the pool while other areas will contain no chemicals; thus making both types of water potential health hazards.

Consult with your pool builder, pool technician, owner’s manual, or local pool supply store for more information on this topic. Typically they will want to know your pool size, the size of the pump/motor on your filtration system, and the number of hours you run your pump and motor.