Can't keep PH down

gsmiley · May 17, 2011

Last year I started the BBB method with great results. For some reason, this year, I can't keep the PH down. Its always around 8.0 and possibly higher since my tester stops to 8.0. I've been following the suggestions from the pool calculator on how much muriatic acid to add, but the PH still goes up. The pool looks great, but know this isn't right. Losing about 2ppm of FC every day if thats any indication of the problem. HELP !

FC 3.0 (normally keep it around 8, I live in Phoenix az)
CC 0
TA 90
CH 250
Borate 50
PH 8.0
cya 70

dmanb2b · May 17, 2011

Get that FC back up to 8 or so pronto :lol:

On the PH issue, TA at 90 is not so high but could be lowered if your PH is climbing. The solution is to reduce TA by continuing to add MA. Try lowering it to 7.2 the next time you add MA. Do you have a lot of water features or run a SWG? As you likely recall, areation or SWG tend to cause PH rise as well.

JasonLion · May 17, 2011

Do you have a waterfall, negative edge, or other water feature creating a lot of aeration? Do you have new plaster in the last year? Those are the two things that commonly cause PH to go up.

If you haven't been able to get PH below 8.0, you just need to be using more acid.

zea3 · May 17, 2011

Also check the strength of the MA you are adding. It should be 31.45% strength.

anonapersona · May 17, 2011

If tap water is high TA, it rises each time you add water. Mine is 340 TA. I add about 2 cups of MA pretty much every time I add chlorine. Sometimes more sometimes less, sometimes I skip because I am lazy but 2 cups MA in 23K gallon pool 2 to 3 times a week. Sometimes I hit it hard and add a lot, 4 cups or more, to drive it to 7.2. Do keep measuring your TA regularly as it will keep changing and that affects how the MA changes pH, quite dramatically.

gsmiley · May 18, 2011

Thank you for all of your replies.

CC is back up at 8.0. Had it at 3.0 cause I read somewhere reading PH at a high CC level is not accurate. I do have a waterfall that is on when we swim, I guess I have to add MA all the time. As for TA, I could be wrong, but thought I had to keep it from 70-90 since I live in a arid area. The PH is down to 7.6 again, I just don't recall going through this much trouble last year.

JasonLion · May 18, 2011

I hope you mean FC everywhere you said CC. Reading PH when FC is 8 is fine. PH readings start to be off a little when FC is above 10, and off significantly when FC is above 18.