Amount of Acid Required - Zero Alkalinity Treatment

[fmartine]

Moved from the Deep End thread: The Zero Alkalinity Acid Treatment

Wanted to confirm the numbers calculated above. Using the Pool Math App It shows that much more Acid is needed to get to Zero Alkalinity and 4.5 pH. Starting with 100ppm of Alkalinity and 7.4 of pH 4 gallons of 31.45% acid will get you to 5.85pH. To get to 4.5pH it says I need 16 gallons.

 

[ajw22]

I would not reply on PoolMath for acid calculations changing pH more than 0.5 or for lowering pH below 7.2. PoolMath calculations are complex approximations and as you get outside the range it was designed for you get errors introduced.

 

[JamesW]

1 gallon of 31.45% acid added to 20,000 gallons will lower the TA by 25 ppm.

So, 4 gallons will lower the TA by 100 ppm, which will make the TA zero and the pH 4.5.