Extremely high TA fill water - Initial fill strategy?


Gold Supporter
Jan 7, 2012
The Woodlands, TX
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Getting ready to fill my pool in a few weeks. Tested my fill water with a TF-100:

pH: 7.8
TA: 330
CH: 75

This gives a CSI of +0.32

Any suggested strategy during the fill to rapidly reduce TA without an excessively low pH?


Well-known member
Jul 20, 2020
Houston, TX
I do not have an answer sorry, but would like to follow along and learn. Perhaps this may be a thread that you could move to "Testing and Balancing" to get more info.


Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
What you'll do is lower your pH to 7.2 using muriatic acid. This has a side benefit of also lowering your Alkalinity. Then using aeration you'll raise your pH again. Each time you lower the pH you'll lower the TA over time. You'll probably need to do it on occasion as you add more fill water to the pool to make up for evaporation and splash out, and your fill water will introduce high alkalinity again. Buy 31% Muriatic Acid for the fastest results....no need to deal with the namby pamby lower strength MA as it costs the same as the stronger stuff but you have to use twice as much.

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Gold Supporter
May 20, 2020
Katy TX
Pool Size
Liquid Chlorine
I am in west part of Houston however my fill water is just at 200 TA - not over 300 as you have given for north Houston. As mentioned above by @YippeeSkippy you will need to add the MA to drop TA and then aerate to increase pH. Do you have a separate water feature with its own pump? I have a waterfall that draws pool water from the side in the shallow end. Once my water is above that suction point I can turn on my waterfall to create a lot of aeration to raise pH while the main pool circulation is off. Maybe you have a similar setup or can configure your valves to flow a water feature (if you have one) to create aeration while you fill. If not, put on any type of water feature you may have once the pool is full. Having initially high TA is not the worst thing and it can be brought down in time. You will need to watch this as you add water during the hot months. Also, be mindful of your CYA and CL levels after your fill is done.
If you are really worried about it, you can put a sump pump in the pool and then have the return be a fountain back into the pool. This type of aeration may be beneficial. Hope this provides you some ideas.
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Bronze Supporter
Jun 1, 2018
Hernando, Ms
Once it’s filled you can play around with PoolMath & determine how different changes will affect your csi . Lowering the ta like Maddie suggested is the first step.
You will also have a protocol for new plaster to adhere to possibly by your pool builder.
Here’s a guide to read as well 👇