OK. So here is my diclaimer. I'm telling you this so that you don't make the same mistakes that I did.
I've had my pool for five years. It wasn't until last year that I became aware of CYA, its purpose, and its effect. Up until then I was lucky. I didn't have a problem for the first three years, did what the pool people recommended, and thought all wa normal. But last year I started having algae problems. And that is when I became aware of CYA. I was told by the pool store, I don't want to slander anyone, that I needed to drain 50% of my water because my cyanuric acid level was up around 120 ppm.
They were right, but at the same time they were also the cause. All pool stores and the chemicals they sell. I'm not going to mention any one in particular because you know their names. They all sell pretty much the same stuff and, according to them, it's a higher grade than what you would anywhere else. Which is true to a point, but in the end they all add cyanuric acid to your pool.
I started buying the 3" tri-chlor tabs at a local wholesaler because they were cheeper. And aren't we all. They were also more dangerous because their effective chlorine was 85%, CYA 10%, and other stuff 5%. This contrasts the pool stores 90% chlorine, 9% CYA, and 1% other stuff. When they come down to it they both do the same damage. Adding CYA.
So I learned that CYA doesn't go away and only accumulates over time. But since it was toward the end of the season I figured I would drain the pool this year if it was necessary. I knew it would because CYA doesn't go down only up. Closed pool at CYA level 120 ppm.
Opened pool this season and much to my suprise, my CYA was reading 10 ppm. Much to my delight I thought that people really don't know what they are talking about. If CYA never goes down, how did this happen?
So I plowed ahead, starting up the pump, adding Chlorine tabs, and thinking I was the luckiest guy in the world cause my pool proved the all the experts wrong. CYA does go down! Right?
Wrong. Through this website I learned that CYA converts to amonia over time and that is what it did in my pool. Cyanuric acid levels were low and I had no idea that amonia was present in my pool. So similar to high CYA, preventing chlorine from being effective, cyanuric acid converts to amonia, the amonia combines with the chlorine being introduced into the system and creates chlorine lock, which renders the chlorine ineffective.
I was pumping chlorine into the pool water, but couldn't read any chlorine. I had plenty of combined chlorine, but no free chlorine. No I didn't superchlorinate because everything looked good at startup. My cyanuric acid levels started to rise quickly and in a couple of weeks went from 10 ppm to 120 ppm again.
My water turned a disgusting green very quickly and this is where the mistakes began to perpetuate.
I had already begun to watch videos on clearing up the pool water using liquid bleach or liquid chlorine. Since liquid chlorine was much stronger, 12% vs. 6%, off to the pool store I went. I had a plan. I forget at this point, I think I already drained and refilled the pool, regardless, I got the CYA level down from 120 ppm to 70 ppm.
At the pool store I told the sales clerk what I was doing and the condition of my pool. I was not 100% confident with the information that I had regarding clearing algae or in my ability to do it. I mentioned to the clerk that it may take me a week or so to get the pool clear and that is when I was derailed. He told me he could get me clear of algae in about 3 days without too much effort. I know he has a reputation as a knowledgeable guy and has been working for the store for about 20 years, and I listened to him, and he talked me into changing my strategy and buying his solution.
So I bought the blue colored crystal concaution for about $35.00 and 6 bottles of liquid shoch for about $30.00 and I did what he told me to do. It worked. It cleared my pool, but it didn't solve my problem, which is why I am telling you this.
My CYA continued to rise, up to 88 ppm, and algae began to come back. I went back to the pool store and they checked my water telling me I had phosphates in my water and he tried to sell me more product to remove the phosphates. He said they were equivalent to algae food. Everything costs $30.00 and at that point I stoped.
I went home, got on TFP, drained the pool, got the CYA down to about 30, got the Taylor K-2006 test kit, and started slamming. Save yourself $100.00 and don't listen to the pool guy. He's just gonna sell you stuff and perpetuate your porblem. Take matters into you own hands, take control of your pool, get the cyanuric acid levels down between 30 - 50 ppm, and I'm going to donate.
I am very pleased!