How do I lower alkalinity, acid not working.

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
9,782
Northern NJ

Acid always works. It is science. If your TA is not lowering it may because you have high TA in your fill water.

What test kit are you using?

Post a complete set of pool water tests as well as your pH and TA of your fill water.
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,929
NW Ohio
Acid lowers TA 100% of the time it is used. If the pH goes down, so did the TA.

What is your TA and how are you going about attempting to lower it?
 

aeh0603

Well-known member
Apr 6, 2016
237
San Diego, CA
Here is the link explaining how to do it any why.
How to Lower Alkalinity

Can you explain what you have been doing so far and post your test results? That will make it easier to help you.

Generally speaking you shouldn't have to worry too much about lowering alkalinity. It will come down on it's own as you lower the pH. Acid is the correct chemical to be using and the only one that will work to lower alkalinity.
 

Rocket J Squirrel

Bronze Supporter
Jun 7, 2018
522
Alamo, CA
Acid always works. It is science. If your TA is not lowering it may because you have high TA in your fill water.
Acid lowers TA 100% of the time it is used. If the pH goes down, so did the TA.
I believe in science. My pool does not. My TA will not lower below 110 no matter how much acid I add, and I've been trying to lower it since April 2018. pH does indeed lower as expected. My fill water has TA of 40. I can't explain it and I've given up trying.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,212
Bedford, TX
RJS,

Lowering TA takes me about two days of work... One dose of acid is not enough... Here is what I do..

Test pH and TA and record the levels. Add enough MA to get to lower your pH to 7.1 or 7.2. Turn on all the aeration you have and leave it on. In about three hours measure and record your pH and TA again.. if your pH is 7.4 or 7.5, add MA to reduce to 7.1 or 7.2 again.. (If your pH has not increased to 7.4, test again in half an hour).. Keep this up all day, every three or four hours until bed time... Leave aeration on.. Get up the next day and start all over again and again...

The first few times you test TA it will not come down much.. but, the longer you do it the faster it will drop..

Thanks,

Jim R.
 
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kb109

Bronze Supporter
Dec 24, 2018
352
Columbus, OH
I had this issue (see previous posts) and it took a lot of time and money (and a little help from some heavy rains) to drop it and I’m still not there yet but very close lol. Mine was 250ish at the beginning of August and just hit 130 during my weekly test last week!! Of course I’m getting close as the season is almost over lol. Anyways, go swim and have fun! Just make sure your chlorine and pH levels are balanced. I worried way too much about my TA.

P.S. I used (and continue to use daily!) dry acid instead of Muriatic Acid (it scares me lol). Had I used it, I could’ve accomplished this much sooner!
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,747
Sebring, Florida
I believe in science. My pool does not. My TA will not lower below 110 no matter how much acid I add, and I've been trying to lower it since April 2018. pH does indeed lower as expected. My fill water has TA of 40. I can't explain it and I've given up trying.
Water is water.....your's is no different than anyone else's. Acid is acid....we all buy the same stuff. Acid lowers the TA in water. You have a testing error or some other factor going on......your pool is not smart enough to defy science.
 

Rattus Suffocatus

Silver Supporter
Jun 5, 2019
400
Corona de Tucson, AZ
If you have some way of aerating the pool from the returns that will help you too. At this point, I only have a 250 gallon hot tub on line, but I have chased my tail on getting TA reasonable more than once. There are two ways to do it.. let the pH creep back up over a day or two and hit it again, or take it down to no lower than 6.8 and aerating the water until it's back up to 7.5 or higher and repeat until that takes a long time. It takes hours that way instead of days. Now if that is feasible on a large pool? Well, I'll find out in a couple of weeks. One of the first things I plan on building for the pool is a PVC aerator for a return or three...

My fill water runs 170-180 TA and that is the only way I can get it reasonable for CSI purposes in a reasonable amount of time (and the wild swings don't happen when you are at 80-90 TA either). I was using dry acid and it really didn't work well, even in the 250 gallon tub. Now I literally dose fractions of a teaspoon of 31.25% HCL into a large 64 oz drink glass from a gas station full of RO water and slowly add it into the tub. And the only downside is that the calculators seem to have a fair bit of rounding error (at those small levels), but it seems to be on the "too low" of a dose side, so I have to do this twice each time. I.E. if it shows I need 1.2 teaspoons (I convert the fl oz to teaspoons via Google) I usually need slightly under two...

But acid is acid and you will get it down eventually. You probably have very high fill TA like I do and you need to do this more often or you need to outgas the carbonic acid in the water as CO2. It's a pain to have pH go to low when managing pH, I can attest first hand to that.

By the way when doing this, it is helpful to have an electronic pH meter and use the titration tests only to verify at the beginning and end.