CYA Question


New to TFP and I have a few questions regarding stabilizer.
I completed a test, all except for calcium hardness, and here are the results:

FC- 6.5
CC- 0
Ph- 7.5
TA- 120
CYA- 20

I have a SWG so I clearly need to get the CYA up. Here are my questions:
When completing the test should I not be able to see anything at all in the bottom, or just until the edges of the dot are no longer visible?

According to poolmath, I need 176 oz (by weight) of CYA. Should I put this in in two doses, testing between? (I have already learned to put it in a sock in front of a return jet.)

Is the Clorox poolcare stabilizer that is available at Lowes acceptable? They have it in 5.5 lb containers, which is exactly 88 ounces.

I know that the CYA will lower the Ph, but it looks like my TA is high, so I can just aerate to bring the Ph back up and take some of the TA back down, right?

Thanks for any help with this! By the way, I think my signature is right, except I will have to add that our pool is in-ground. I do that after this post.



TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
The dot should disappear.

You are wise not to add all the CYA at once. The pool may not be as big as the builder claims. It's easy to add more, hard to remove excess. As long as the label says cyanuric acid and is 99% or better, that's the stuff. As long as you don't block all the flow, you can just the sock in the skimmer basket. It's less work that rigging it up in front of a return. Just leave the pump on the whole time, or fish the sock out and set it in a plastic bucket if you need to shut the pump off.

As an aside, the stuff dissolves fairly slow, so the pH will not drop all the sudden. The high TA will work against that and you might not even have to aerate to bump the pH back up.