Where's all my stabilizer?


Bronze Supporter
Jul 25, 2015
Orlando, FL
Filled pool last year after refinishing to pebble and got CYA to around 50 (overshot some, really wanted 40).

This spring I notice the pool is consuming chlorine a lot faster than I expect. Test the water and there's basically no CYA at all. Local pool store confirmed the numbers. I don't use pucks.

By all accounts I've read, only way to rid myself of CYA would be to drain water and that hasn't happened. Virtually no rain over the winter.

Where'd it all go?


TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
NW Ohio
How long has it been since the last time you tested your CYA before this last test?

Also was there any time between then and now that you have tested your water and found 0 FC?


Silver Supporter
Mar 14, 2016
Chino Hills, CA
I'm by no means an expert but I believe by dilution of water can make your cya go lower. If you have a leak and an auto-fill keeps filling it up, splash out and refill or a lot of rain water in the pool. I'm sure the experts will chime in but that is what I think can make your cya go away.

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Bronze Supporter
Jul 25, 2015
Orlando, FL
I don't recall but it would have been in the late summer or fall 2016. It's a number that doesn't (or didn't?) move around much so I kinda set it and forget it. The prior year I had horrible problems with CYA because I was addicted to pucks and didn't know any better. Local pool store just keeps selling pucks and my CYA was over 300. Wasted a lot of water fixing that...

- - - Updated - - -

I don't have an auto-fill and AFAIK evaporation does not reduce CYA. No leaks.

ship of fools

Well-known member
Nov 9, 2011
Albany, NY
AFAIK evaporation does not reduce CYA. No leaks.
It does in that you replace the water that evaporated with water that has 0 CYA. I don't think that would explain your fall to 0. If you said you tested in May, didn't add CYA and then had your torrential downpours every day it would explain some of the loss but again not enough to go to 0.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Not often, but sometimes CYA is consumed by bacteria in a pool that has been neglected (got really dirty) for a while. Do you have that condition over the winter?