Just before closing our pool last fall I had the cyanuric acid level tested at a pool supply place--they said it was 77 ppm. We just opened the pool and I had the water tested at the same pool place. They say the CYA level is now at zero ppm. I had them test it again one day later and they still say the CYA = zero. We normally drain out something like 15 or 20 % of the water for winterizing so if the result was 60 ppm or so I would not have been surprised. I thought something must be wrong with their test set up. However, I shocked the pool to about 25 ppm chlorine and two days later the chlorine was 0 ppm. I then added enough chlorine to bring the level up to 9 ppm and retested the chlorine level about three hours later and it was 0 ppm. Most amazingly, the sun was not out during that time. So it really seems like I have no stabilizer left.
How could all of my CYA have dissipated over the winter? It's my understanding that the ONLY way to get rid of CYA is to drain out the water containing it and replace it with fresh water. As mentioned above I only drained out a fraction of the treated water and it was replaced with snow melt and rain water. What is going on here?
How could all of my CYA have dissipated over the winter? It's my understanding that the ONLY way to get rid of CYA is to drain out the water containing it and replace it with fresh water. As mentioned above I only drained out a fraction of the treated water and it was replaced with snow melt and rain water. What is going on here?