Lowering Alk -- fountain or ripple

[JohnT]

Why should I expect PH to go up? I think I'm confusing myself. Let me ask this:

If I wasn't aerating and added muriatic acid to address my high alkalinity, should I expect my PH to go down THEN? Because, like Carl says, alk and ph sort of tag along together?

... but by aerating I will combat the tendency for the ph to drop because of the added acid?

sorry. just trying to get my arms around this so it makes sense and I can remember it.

Normally, pH and alkalinity move together, so when you add acid, they both go down. (You'll have to look at Ben's stuff to get the exact details, but here's my recollection of how it works) At lower pH, aeration causes carbon dioxide gas to be given off by the water. This removal of carbon is what actually helps. The aeration process raises the pH, but since the carbon has been gassed off, your TA stays down.

[jenmenke]

Normally, pH and alkalinity move together, so when you add acid, they both go down. (You'll have to look at Ben's stuff to get the exact details, but here's my recollection of how it works) At lower pH, aeration causes carbon dioxide gas to be given off by the water. This removal of carbon is what actually helps. The aeration process raises the pH, but since the carbon has been gassed off, your TA stays down.

So how long would you expect it to take for six small fountains (think large drinking fountain action) to raise the alkalinity from 7.2 to 7.4 in a 40,000 gallon pool? Days? Weeks? I have no idea.

I've lowered the alk from 240 or so to 160 with 2 gallons of muriatic acid. the ph went down from 7.3 to maybe 7 or 7.1. I've had the fountains on all day for the last 3 days. Would you recommend more acid? We DO have a heater and we HAVE blown out a heat exchanger from bad scale. That was in 8 weeks or so of use the first season. The pool company paid for it that time because they were the ones that told me that if my water was clear and ph was in range, I was fine. I found this site shortly after that. I just don't want the same thing to happen again. I would guess I still need to add more acid?

(oh and by the way, the last question I asked about shelf life? That older acid was completely bad. So I answered my own question: Yes acid has a shelf life, or it completely degrades when exposed to heat and/or cold)

[sparks999999999]

So how long would you expect it to take for six small fountains (think large drinking fountain action) to raise the alkalinity from 7.2 to 7.4 in a 40,000 gallon pool? Days? Weeks? I have no idea.

Newb here <wish i knew about this site a couple weeks ago> anyway i am interested in the answer to this question as well - how long does it take? Hours, days, weeks - or do you simply keep checking until PH stops increasing?

Thanks.

[waterbear]

Newb here <wish i knew about this site a couple weeks ago> anyway i am interested in the answer to this question as well - how long does it take? Hours, days, weeks - or do you simply keep checking until PH stops increasing?

Thanks.

Read this thread for the proper way to do it
http://www.poolforum.com/pf2/showthread.php?t=191