Help me with PH Bounce

Ed Phillips

LifeTime Supporter
My PH goes from 7.4 to 8.0 Every night, If add PH decreaser in the morning to get it back to 7.3 /7.4 range it stays all day without going up but maybe to 7.5. But in the morning it will be right back at 8.0. I have a digital PH meter calibrated perfectly to 4.0 and 7.8 and double check with the test kit.

Here are my numbers after a heavy bather load yesterday ( 20 + ) I added the same amount of PH decreaser last nite that I always have to add so it was at 7.6 this morning.

FC 8
CC 1
TC 9
PH 7.6
T/A 110
CH 230
CYA 30

ORP 710

Salt 3200 PPM

Ozone Generator on all the time.

Chlorine Generator set to 30%

Water Temp 90
Air Temp 70

25,000 Gal Plaster Pool.

I only operate the Waterfall if we are in the pool so its off 90% of the time.

Water in Pool for about 1 Month.

The PH has been Bouncing up and down like this since we filled the pool, Never has been below 7.2 but is usually 8.0.

What should I try to keep the PH a little more stable?



TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
If you lower your TA to the 70-80 range that should help noticably. Low PH plus high TA plus a SWG will make the PH go up.

I would suggest raising your CYA up to around 60 to 80. That will allow you to turn down the percentage on your SWG, which will increase the cell life and also help slow the PH rise.

Unless you reguarly have that many people swimming you can also lower the FC level, which will also help slow the PH rise since the cell will be on less often.