Can TA be too high?

Uncle Ben

Well-known member
Apr 20, 2010
Southern California
The recommended level in pool school for my type of pool is 70-90+

In my case, it is currently about 120, and was closer to 150 several days ago. Is there a point where it is considered too high?

Current levels:
FC: 5
CYA: 40
pH: 7.4
TA: 120

(don't know CH at this time)


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
How high you can let TA go depends on a number of other factors. The most important one for a plaster pool is balancing TA and CH levels. If TA is high you don't want CH to also be high at the same time. If you are in the situation where both TA and CH are high, since TA is easier to lower than CH, you need to set an upper bound on your TA level, rather than lowering your CH level.


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
Yes, there is a point where it's too high - when CSI starts going positive. Plug your test numbers - including water temperature - into Pool Calculator and see what CSI is.

The water here in SoCal is hard, so I can assure you CH and TA are going to be high. Test the water coming out of the hose next time you add water, just so you know what it is. If the tap water is 300 CH, there's no point shooting for 250.

Then punch numbers into the target zone of Pool Calculator to see how to get CSI down. CH is going to climb through evaporation and refill. Temperature is going to climb and there's not much you can do with that. Which leaves you with TA and pH to adjust. So buy a couple gallons of acid. It will get used up.