CYA question

[waterbear]

The drop is probably pretty much done. I can't explain the chemistry behind it, but I do know that addition of CYA has very little, if any, effect on your pH. And what little effect you might have seen will be countered by the natural pH rise from a SWCG anyway.

Just to clarify, SWCGs don's cause pH rise, outgassing of CO2 does. SWCGs increase aeration and that increases outgassing.

[Goolsbymd]

I know I need another lb of CYA I just wanted to add 90% see how it effects chemistry then add the last bit so I didn't over shoot. I did use the effects of adding chems to double check things.

[Goolsbymd]

Waiting a week, what is the reason for that? So the CYA goes through the sand, right? I have a cartridge filter so I would imagine once it is dissolved it's all in the pool? Or does CYA have some kind of don't know how else to say it but like a timed release to take effect?

[waterbear]

Waiting a week, what is the reason for that?
CYA can take up to a week to FULLY dissolve. Just a safety precation so you don't overdose.

So the CYA goes through the sand, right? I have a cartridge filter so I would imagine once it is dissolved it's all in the pool?
The undissolved CYA will get caught in the filter, be it sand, cart, or DE and stays there until fully dissolved.

Or does CYA have some kind of don't know how else to say it but like a timed release to take effect?

No, it just gets caught in the filter and slowly dissolves there. Wait a week and retest. It's not rocket science.

Even if you put it in a sock as some do (and IMHO, usually unnecessary, just pour it SLOWLY into the skimmer with the pump running) it will pass though the cloth and some will still end up in the filter and dissolve there. It often is all dissolved in a few days but waiting a week is good insurance against overdosing and needing to drain.

[aylad]

Just to clarify, SWCGs don's cause pH rise, outgassing of CO2 does. SWCGs increase aeration and that increases outgassing.

Yeah, I know, maybe I should've stated it more clearly--just trying to keep things as simple as possible

Jan