High pH - used wrong soda


Well-known member
Jun 24, 2019
Simi Valley, CA
I used PoolMath to calculate the amount of soda that needs to be added to bring my pH from 6.8 to 7.4, but I didn't pay attention that it is Soda Ash that was recommended and not Washing Soda that I used. It has been a day since then with a total pump run time of several hours. My pH is now 8.2. What should I do in this situation? Below are test results of this morning. What should I do in this situation?

FC: 3
pH: 8.2
TA: 90
CYA: 50


TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
NW Ohio
Yes, that washing soda is the same as soda ash. It's all sodium carbonate.

Odd that your pH would be that low with TA that high. What are you chlorinating with? Speaking of chlorination: raise your FC. FC/CYA Chart


TFP Expert
Mar 2, 2011
A pH of 6.8 doesn't make sense with the TA at 90. Probably test error.

Why would your pH be that low?

How are you testing?


TFP Expert
Mar 2, 2011
It's unlikely that the pH was that low unless you have used acid or trichlor tabs.

Be extra careful with test procedures. Be sure to rinse before and after doing every test.