phosphates high? ph low

[mrszaff]

Hi, I am replying to this old thread I posted last summer because I cant seem to post a new one and the question is similar....15x32' rectangle 19K gal IG vinyl pool
My question is about CYA of ZERO, how much should I add and do you recommend any from amazon?
My other levels are FC 2; TC 2; ALK 50; Ph 7.4; copper 0; iron 0 phosphates 500; Cal hardness20

[CarlD]

Any CYA powder that's 100% Isocyanuric or cyanuric acid is fine.

The question isn't how much you should add, but what level of CYA do you desire. Usually, in a location like yours, something between 30 and 50 ppm is a good target.

[FormerBromineUser]

.
An additional thought: Consider adding less CYA than you think you need so you don't overshoot your goal. You can always add more in a later if you need to. CYA levels don't naturally lower that much over time.

I undershoot with all my additions except chlorine. Call me over-cautious if you will...