Help raising PH and TA


May 15, 2007
Long Island, NY
FC: 18
CC: .5
TA: 70
PH: 7.0
CH: 60 (should I be concerned about this?)
CYA: 50-60

When I tested before shock cycle the PH was reading 7.2, I believe the test is bleaching out now but I still want to raise it due to the rains we received last night. So how much washing soda should i put in to raise the PH .3 PPM? I read Chem Geeks explanations but I cant wrap my head around what is needed for my pool..
Also, should I be concerned about my extremely low CH level?

Thank you!

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
San Rafael, CA USA
Assuming your numbers are correct and that the pH is really 7.0 (TA is 70 and CYA is 55), then it would take 85 ounces weight (5.3 pounds) of 20 Mule Team Borax in your 26,000 gallon pool and will also raise your TA to 77. If you already had some pH Up (sodium carbonate or Washing Soda) product and wanted to use that instead, then you would need 43 ounces weight (2.7 pounds) and this will also raise your TA to 82.

Note that if you are starting with a pH of 7.2, then the above amounts will raise your pH to 7.66 which is why the calculation is not straightforward. It depends on your starting pH, TA and CYA levels (and Borates, too).

The safe thing to do is to add less then you need, let it circulate and equilibrate for a few hours, then retest (or just test the next day).


pH does not 'bleach out' with high santizer levels when using liquid reagents but can read higher than it actually is because of a chemical interaction between the pH indicator and the chlorine or bromine in the water. If you were getting pH readings of 8.0 or higher I would suspect this interaction but since your pH is reading low I would start raising it.

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
Northern KY
Now that you mention pump parts, I seem to recall something about heaters... I don't know about either, only that a liner pool does not have a Ca requirement.

Someone else will be along to add to my lack of information!! :)