MA - How much too add at one time?

jjdurrant

LifeTime Supporter
Apr 27, 2008
575
MN
#1
I thought I read 3 cups at a time was recommended. However, a recent member added a gallon and no one threw up a red flag.

Thanks!
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
The old rule of thumb limit is one pint per 10,000 gallons at a time, perhaps a quart per 10,000 gallons in extreme cases. However, the higher your TA level, the more acid you need to achieve the desired result. If you have a reliable TA reading that shows extremely high TA levels then using more acid at one time makes sense.
 

jjdurrant

LifeTime Supporter
Apr 27, 2008
575
MN
#3
my TA is 210.. it is dropping albeit slowly. The most I have added at one time is three cups with six cups being the max in one day. Maybe time to step it up"?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#4
When lowering TA you want to target a PH of between 7.0 and 7.2. After a couple of cycles of lowering the PH you should be able to get a sense of how much acid it will take to make a given PH change. Even keeping in mind that the amount of acid you need to use goes down as TA goes down, that will still be more accurate than using the Pool Calculator.