Quote Originally Posted by Tredge
I'm also dealing with a high TA.

Are you also adding CYA? I think this will make it look like your TA and PH are going up when they are not.
Nope, only using bleach. CYA is about 20ish and holding.

Aerating actually causes your PH to go up. The only way Aerating will work is to keep adding Acid....if you can keep the PH low for a period of time then the TA WILL drop. It can take weeks.

Shoot for a constant PH of 7.0 (6.8 for a plaster pool) and watch your TA closely. When it starts to drop it will drop significantly.
Also remember that TA isnt a thing, its a measurement of the waters resistance to changing PH. It can go back up and in my experience will bounce around a little while you are trying to stabalize the PH.
I had to add 3" of water to make up for evaporative loss last night. Since my fill water is highly alkaline and lower PH than my pool, I waited until it was circulated and retested. PH was down, Alk was 190.

The Alk number doesn't bother me (vinyl liner), but the PH tends to shoot back up within days, so I'd like to get it down to 100 or so and see if my PH stays more stable. Water clarity and feel is much better when I keep the PH between 7.2-7.6 ish.

I set up my sump pump to aerate, but we have a good chance at thunderstorms today so I'm waiting to add acid and start aerating until I see what the rain does to the water. If it doesn't have much affect or misses us again, I plan to attack the alk daily until it drops to where I want it.

This is all from info I've gleamed out of this forum, I'm still working on it myself.
Thanks. I try to read as much as possible before asking questions, but this one has been stumping me. I'm starting to think it's primarily the high starting alk that is making it so hard to keep alk down permanently (ie, without adding fill water). Once alk is lowered and properly aerated, it shouldn't rise sharply, right?