CYA just doesn’t go down?

Poolsnotmygame

Active member
Apr 25, 2019
34
Massapequa, NY
Hey guys, so let me start by saying I know 80-90 cya is not ideal. I’ve kept stabilizer chlorine out of the pool and only have been using liquid chlorine. I drained some water off the top and with the relentless rain the northeast had been getting. I thought maybe the cya would eventually come down on its own. But it hasn’t. Like at all. Is there some other way that I can expect the cya level to drop with out me emptying my 40,000 gallon pool and refilling because that just seems ridiculous to me.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,446
Bedford, TX
pnmg,

It matters little what you and I think, it is a scientific fact... :mrgreen:

CYA will degrade a little on its own, and rain and overflow will also reduce it a little, but for any quick major changes, the only option is to drain the pool enough to get the CYA where you want it..

Thanks,

Jim R.
 

Poolsnotmygame

Active member
Apr 25, 2019
34
Massapequa, NY
pnmg,

It matters little what you and I think, it is a scientific fact... :mrgreen:

CYA will degrade a little on its own, and rain and overflow will also reduce it a little, but for any quick major changes, the only option is to drain the pool enough to get the CYA where you want it..

Thanks,

Jim R.
Man, oh man. How much of the pool do I need to drain to get it down to 50? Is there a way to figure this out? Is it really that important that I get the cya down?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,069
San Dimas, CA (LA County)
If you don't have algae, you can maintain it with that high CYA. I had to my first season, due to water restrictions and drought. And I was north of 220 CYA. It's not ideal, but it can be done.

Maintain adequate chlorine FC/CYA Chart because if you do get algae, then you really won't have a choice but to drain a bunch. You'll also have to test pH when you're at the low end of adequate because the pH test can get weird above 10 FC.

If you choose to lower CYA, how much to replace is simple arithmetic, since tap water has no CYA. If you want to lower CYA to 60, replace a third. You can also try working it down a few inches at a time. It's not as efficient, but if you're on a well, it may be the only way.
 

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
805
Rancho Cucamonga, CA
As Richard said, 80-90 CYA is manageable. My CYA was at 120-140 last year. I converted to TFP and managed the pool a full year with clear water and no algae. Once you're at your target level, you won't use more chlorine than you would with lower CYA. Just make sure you stay on top of FC levels.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,847
Sebring, Florida
While you can manage a pool with CYA 90, why would you?

You need to drain about 15K to get your CYA to 50......what does your water cost? There's a decent chance you can do that drain and refill for less than $100 and not struggle with significantly more chlorine loss (if you keep CYA 90) for the swim season
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,847
Sebring, Florida
and not struggle with significantly more chlorine loss (if you keep CYA 90) for the swim season
I worded that very poorly. You will lose more chlorine keeping a CYA of 90 rather than CYA 50. That is not intuitive but it works out like that.