Dealing with high pH

[docelect]

My pH goes from 7.6 to 7.8 in about 3 days, then on up to 8.0 (if I would let it). I add 40 oz. of muratic acid to return it to 7.6 from 7.8 (30,000 gallon pool).
FC = 4.5 (Hayward SWG)
CC = 0
CYA = 50
TA = 90
CH = 30
pH = 7.8

Is it normal for this to happen in the summer? Its already 90 F here in Mississippi, with high humidity. I get about 2" of evaporation per week. I know the CH is extremely low, but I have a vinyl liner, and our water here is extremely soft. Is there anything to do to keep from having to add so much acid? The pH lowers as calculated when I add the amount of acid indicated by the Taylor test.

 

[jblizzle]

Pretty normal, especially with a SWG that is causing aeration which drives the pH up.
You could raise the CYA up to recommended levels and reduce the SWG output which should result in less aeration and slow the pH rise.

As you keep the pH in check, the TA should also get lowered which should also slow the pH rise.

 

[Patrick_B]

Yes, very normal I agree.

Once the TA is down a little it will slack up on rise. Still, there is nothing unusual with that at all.

 

[poolnoob.ca]

I have found the same thing with my swcg so I did the borax treatment to buffer the pH, in addition to the other benefits it brings http://www.troublefreepool.com/threads/4655-So-you-want-to-add-borates-to-your-pool-Why-and-How