Lost my CYA

numberonenole · May 31, 2011

I couldn't figure out why I was using so much liquid chlorine (put in 2 jugs of 2 1/2 gallon 10 percent before I went out of town for 2 days) until I tested my CYA (which was around 50) and now it is 0. FC was also 0 but that's no surprise with fun sun, 90 degree temperatures, and 0 CYA.

Is there something out there that eats CYA? I have not had this problem in the past and searching the forum I couldn't find anything similar. I have not backwashed that much. Instead I have had to add water due to evaporation (I don't think it is ever going to rain again at my house) and a leak we had to fix.

I'm off to buy more CYA and chlorine. I'd appreciate any thoughts! Thanks!

Bama Rambler · May 31, 2011

There have been reports of CYA going to zero. Most of the times it's happened over the winter but Richard (Chem Geek) had it happen to him.

How are you testing for it?

numberonenole · May 31, 2011

Thanks for the reply!

I have the TF-100 test kit. I had to buy extra R-0013 last year and the lid to the large bottle has broken. Could that make it go bad so the test isn't accurate?

I already added liquid CYA earlier this year, then added another big bottle of granules. I had a pretty good leak and lost a lot of water so I wasn't surprised to have to add so much at the begining of the season. I am shocked to see it all gone now, though.

I know I have been fighting algae. My pool looks clear, but there is algae under my wedding cake steps (I have three sets in the pool) so I have been trying to swish under them and keep the chlorine level up high.

I appreciate any help I can get!

Bama Rambler · May 31, 2011

Can you detect FC after an hour of adding chlorine to the pool?

numberonenole · May 31, 2011

Ran out and checked. I am now sitting at 22 FC.

JasonLion · May 31, 2011

You should start adding more CYA. CYA shouldn't disappear as long as you maintain an FC level. Or to put that another way, CYA should only disappear when FC is zero.

Bama Rambler · May 31, 2011

What he said ^ !

surfhawaii · May 31, 2011

Ok, need some more education. I thought you said the only way to get rid of CYA was to drain the pool.

Bama Rambler · May 31, 2011

The only reliable way to get rid of CYA is to drain or R/O. There are a few reports of some type bacteria converting the CYA into ammonia and leaving no CYA in the water. We don't understand enough about it to replicate it or even know if we could or should try to.