CYA loss from water evap?

kschmidt1

LifeTime Supporter
Aug 2, 2015
162
Grandy, NC
3 weeks 90+ temps, no rain, I have been adding water approx 2 inches per day. CYA had been 40, was adding gallon of bleach per day, testing 6-7ppm. FC numbers started dropping and rechecked CYA and found less than 30. Have my daily water additions caused CYA loss? Also read somewhere CYA loss from warm water. Would it be quicker to raise with liquid stabilizer rather than powder?
Thanks in advance
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
21,960
Laughlin, NV
CYA is not lost due to evaporation. CYA does degrade slowly in pool water and can degrade a bit quicker in warmer water. That and the test is +/-10 ppm to begin with. So a drop from 40 to 30 is not surprising.

Liquid stabilizer is quicker to raise the CYA.
 

homegameroom

Bronze Supporter
Sep 23, 2015
112
Sunrise,FL
That's a LOT of water to add each day! CYA can degrade a bit over time (some folks add a little bit annually); could you be losing yours to a leak. CYA does not evaporate.
 

homegameroom

Bronze Supporter
Sep 23, 2015
112
Sunrise,FL
Every now and then even a blind squirrel finds a nut! :)
Once upon a time, I thought my pool water was evaporating that much too - then I found a small leak by the skimmer. No more excessive evaporation!
 

kschmidt1

LifeTime Supporter
Aug 2, 2015
162
Grandy, NC
A 2" water loss per day is a leak. Good catch.
CYA is not lost due to evaporation. CYA does degrade slowly in pool water and can degrade a bit quicker in warmer water. That and the test is +/-10 ppm to begin with. So a drop from 40 to 30 is not surprising.

Liquid stabilizer is quicker to raise the CYA.
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I should have written CYA test dot still showing at 30 so CYA less than 30. Looked at liquid CYA on line, but all seem to be called 'stabilizer and conditioner' is this correct
 

IceShadow

Gold Supporter
Jun 8, 2019
1,060
Milwaukee, WI
Put some water in a bucket and set it on the steps. Mark the water line on the side of the bucket and the side of the pool with some painter's tape. Wait a day and see if they're dropping the same amount or different. If the pool is dropping faster than the bucket you know it's a leak and not evaporation.

A leak would certainly drop your CYA over time.
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,714
Houston, Texas
To answer your earlier question, yes CYA is also called stabilizer or conditioner. If the main ingredient is cyanuric acid, it is CYA. Check the waste line on the multiport valve of your sand filter. That is a common leak point.
 

kschmidt1

LifeTime Supporter
Aug 2, 2015
162
Grandy, NC
To answer your earlier question, yes CYA is also called stabilizer or conditioner. If the main ingredient is cyanuric acid, it is CYA. Check the waste line on the multiport valve of your sand filter. That is a common leak point.
Done. Had pool guy out 6 weeks ago he inspected all ground around pool, waste line and said must be something need to dive to find. I'm not a scuba diver. Guess I need to find someone who can.
 

homegameroom

Bronze Supporter
Sep 23, 2015
112
Sunrise,FL
If you are as cheap as I am, you can try to squirt a little food coloring around areas that would be suspect (with filtration and pumps off, of course) and see if the dye goes away or seemingly gets sucked out. Start with the more obvious areas first (and deeper) and be sure to not stir the water up too much.

You can also tape the bottle of food dye at the end of your skimmer or vacuum pole and bump it a bit at the bottom to release some dye and see if it goes anywhere.

Then you can hire a pro if you can't find anything.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,564
Sebring, Florida
2" daily in an AG pool is an obvious leak. There is nowhere for the water to go except to leak out around the pool, If you can't see that, then I suspect you are not adding 1-2" daily. Normal evaporative loss in your region should be around 1/4".
 

mickey4paws

Bronze Supporter
LifeTime Supporter
Apr 10, 2009
657
S.E. MI
I agree, it definitely sounds like you have a leak if you're adding 2 inches a day.
We had a leak but no stairs for bucket test. So we added enough water to be at the screw at the middle of the skimmer. We ran the pool for 24 hours with pump running, then measured from that screw downwards and had lost 1 5/8 inch of water. Then we added water to get back to that screw and did not run the pump for 24 hours and measured again, and the loss was still 1 5/8 inch.

They have some videos on youtube to show how to use dye to find a leak. You can also go to this link, put in your pool parameters and see how much water you're losing once you've measured the daily loss. Our leak was something like 400 gallons a day in a 20k pool. We tried the dye test but couldn't figure it out (even though it probably would have been obvious to someone else) so hired a leak company. Expensive and then they wanted a lot to fix a skimmer leak. A family friend whose one of those guys who can fix anything fixed the leak and crossing fingers, it's been holding so far. Here's the leak calculator: Water loss calculator
Good luck!
 

kschmidt1

LifeTime Supporter
Aug 2, 2015
162
Grandy, NC
If you are as cheap as I am, you can try to squirt a little food coloring around areas that would be suspect (with filtration and pumps off, of course) and see if the dye goes away or seemingly gets sucked out. Start with the more obvious areas first (and deeper) and be sure to not stir the water up too much.

You can also tape the bottle of food dye at the end of your skimmer or vacuum pole and bump it a bit at the bottom to release some dye and see if it goes anywhere.

Then you can hire a pro if you can't find anything.
Thanks. Tried this before called pool guy as last resort (cheap and cautious):oops: