Does PH ever normalize?

[steveinaz]

Ok, will do. I guess I'm trying to do too much, too fast. The plaster is only 7 days old. I'll run my waterfall, it creates quite abit of turbulence when on full. Thanks Richard, I appreciate you patience and help.

[chem geek]

Well stock up on acid because you'll need a lot! You don't really have to do anything in a rush. With the high TA it's sort of a "pay me now or pay me later" situation. You'll end up adding the same amount of total acid over time to get the TA lower, but doing the aeration will speed that process up so you "get it over with" sooner (i.e. adding a lot of acid in a short period of time instead of less acid per day over a longer period of time). Hopefully when you are done, the rise in pH will be less, but it's really up to you. If you don't mind adding some acid every day that's fine; you'll just be doing that for quite a while, but eventually your TA will drop albeit slowly.

I calculate that for your 12,000 gallon pool with the numbers that you posted that it would take 38 cups of Muriatic Acid (31.45%) to reduce your TA from 200 to 100, along with aerating (outgassing) a little over half of the total carbonate in your pool. So, you'll be adding 38 cups of Muriatic Acid no matter what -- it's your choice of the timeframe over which that is done. This calculation does not take into account the additional Muriatic Acid needed to compensate for the curing of plaster -- that is not an easily predicted number. By the way, the 38 cups of acid plus the outgassing raises the chloride (measured as ppm sodium chloride) by 22 ppm, but the TDS actually gets reduced by 58 ppm due to the removal of (mostly) bicarbonate from the water that exceeds (in ppm) the addition of chloride from the acid.

Richard

[steveinaz]

I'll start the process tonight, acid/aeriate...etc. I'm gonna target TA @ 120ppm since I'll probably have an on-going battle with fill water @ 180ppm. Thanks Richard

Process: http://www.poolforum.com/pf2/showthread.php?t=6588