Balancing High TA and Low pH with acid and aeration - Am I doing this right?

JaceTheAce

Bronze Supporter
Apr 10, 2020
19
Utah
Context

I built the pool in the Spring this year. Stats are in my sig. Our tap water has naturally high TA and low-ish pH. For most of the summer we used Chlorox pucks in a floater for chlorination. Because of the pucks my CYA was getting out of control and pH kept dropping. I stopped using the pucks and switched to liquid chlorine then did a partial drain and refill to get the CYA down.

Here are my current numbers:
FC = 4.0
pH = 7.3
TA = 90
CH = 325
CYA = 55
Borates = 50ppm (from adding Borax)

I'm happy with all those numbers except TA so I've been using 14.5% Muriatic Acid + Aeration to get my TA perfect before winterizing the pool. A week ago my TA was 130. Every day for the past week I've been adding 64oz acid then aerating for 8 hours. After doing that four times I've reduced my TA from 130 down to 90 and the pH is 7.3.

Question: Is it normal/OK to require 2 gallons of acid to reduce the TA in my 7300 gallon pool from 130 down to 90? I just want to sanity check to make sure I'm not missing something. For testing I'm using the Taylor K-1000 TF-100 test kits that I purchased in April.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,561
Fletcher, OK
Normal for your pool :)

Every pool reacts differently, some take more and some take less... Because you have borates it is taking much more acid to move your TA and more aeration to move your PH, that is what the borates do... once you stop dropping your TA you will then be able to see how fast or slow your PH will move or will it stabilize at 7.6/7.7 or so... I think that is what you are trying to accomplish...
 

JaceTheAce

Bronze Supporter
Apr 10, 2020
19
Utah
Normal for your pool :)

Every pool reacts differently, some take more and some take less... Because you have borates it is taking much more acid to move your TA and more aeration to move your PH, that is what the borates do... once you stop dropping your TA you will then be able to see how fast or slow your PH will move or will it stabilize at 7.6/7.7 or so... I think that is what you are trying to accomplish...
Thanks for the reply. I won't worry too much then.

Yes, reasonable TA and perfect pH is what I'm trying to accomplish as we go into winter and the pool is covered for several months. I also had a hunch the borates were part of the equation but I'm new to this so I was unsure. Thanks for confirming. I initially added borates for low pH before I discovered aeration. It is so simple.