How to lower PH

Jun 1, 2012

I already using the calculator but i am still not sure how much mutric acid liquid add to lower my ph. My current ph is 8.5 and want to target 7.5

above ground pool
30,000 gallon water.

many thanks,


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Adjusting PH requires knowing at least your TA level. Then plug you numbers into the Pool Calculator and see what it says. For large PH changes it is best to add about half of what it recommends, give it half and hour to an hour to mix in, test PH again, and continue adjusting from there.


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
A reading of 8.5 could likely be anything over that ad well. So it may require more than you think. You just have to adjust it in a few steps.

Add some, wait an hour, test and add, repeat.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone :)


LifeTime Supporter
Jun 18, 2010
Glendale, CA
I see something like 60 oz total for 30,000 gallons - but with your PH at the high end of what is typically testable you may need more.

Jason's got your covered - add 30oz or so, let the pump run for 30min and test PH again.
Jun 1, 2012
i dump around 60oz liquid acid (2 hours ago) and still long does the acid take effect?. The pump been running since this morning