My pH went from 7.6 to 8.2+

[tcat]

Topic split. Please ask questions in your own topic. Thanks JasonLion

Talk about an old thread... I had searched on pH of bleach and got here. I shocked with two 182 jugs of bleach (Safeway brand because Sam's was too far this weekend), my pH went from 7.6 to 8.2+. Have added 32 oz MA (HD 31%), and it's back down to 7.5-7.6. I have to add about 8 oz. MA per day to keep pH in check (only about 12 oz. of bleach per day). I have no waterfalls or aeration. Is this normal (nothing jives with pool calculator)?

 

[JasonLion]

Bleach raises the PH right when you add it, but the PH comes back down as the chlorine gets used up. If you are maintaining a uniform FC level there is no net change in the PH.

One way you might be running into problems because the results of the common PH test is invalid when the FC level is above 10. That could easily give you the mistaken impression that the PH is very high, when it is actually too low.

Another possibility is that your TA is very high, which can cause the PH to rise rapidly. Fresh plaster (less than a month old) can also cause the PH to rise rapidly.