Help Lowering High TA

no_Wedge

Member
Jun 16, 2012
18
We recently filled up our pool about 6400gal, with well water, and have high TA. I have been trying to lower the TA with Muriatic acid (the percent is <25% as shown by msds). But doesn't seem to be doing much. It has lowered the pH a little, but not like what i thought. Is it better to keep adding it the same day until the pH is lowered, or just a little at a time.
Also the alkalinity showed atleast 240 on my test strip, but i imagine it is 300 or more.

starting stats:
pH ~8.5
TA ~300

I've already added about 90oz over 3 days.

stats now:
pH ~7.8
TA ~240

is there anything i should do different maybe try a better acid?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,053
San Dimas, CA (LA County)
Try the pool calculator. Down near the bottom it will show you the effects of adding chemicals. Plug in what you're going to add, and it will show you how you will lower pH and TA. With high TA, it takes a bit more acid to lower pH, but each time it should need less. Have you read Pool School on Lowering TA?
 

lightingguy

LifeTime Supporter
Jun 17, 2010
513
Glendale, CA
Your test strips are not particularly accurate. Especially when you are on the upper or lower bound of the strip - so it's possible your PH was higher than 8.5 and your TA higher than you think.

Lowering TA is a slow process (not a one time thing) - but you should be seeing your PH respond to the acid as you expect once it's in a range you can test for. If it doesn't it's either testing error or the acid is weaker than you think.

If you are using muriatic acid - then switching to dry acid isn't going to make a difference.
 

no_Wedge

Member
Jun 16, 2012
18
ok i'm adding some more and retesting.
Once the TA is down to a good level, should it be easier to maintain it at that level (minus adding water and rain)?
 

no_Wedge

Member
Jun 16, 2012
18
yea even after testing and adding a quart of the safe MA it didn't have much if any real effect. I'm going to have to find some 31% i guess the stores were all sold out last time i checked lol.
 

no_Wedge

Member
Jun 16, 2012
18
yea about a month ago i checked at lowes and home depot, and someone had bout all they had of the good stuff lol, it looks like they have more now though. Thanks
 

no_Wedge

Member
Jun 16, 2012
18
ok so i got 2 gal of the good stuff, and have lowered the pH to around 7, and have pointed the powerhead up to aerate the water. I think the Alk is closer to 200 or less, but it's hard to tell. What do i need to do now, do i need to keep the pH at about 7 until the alk is lowered, or let it rise back up and just add more acid later?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
The simplest thing to do is to wait for the PH to come up to 7.5 or 7.6 and then lower it back down. You can add acid more often if you want, but it will only speed things up a little.
 

no_Wedge

Member
Jun 16, 2012
18
ok so basically the pH has nothing to do with lowering the TA other than the fact you can't get the pH below 7 without causing problems. Adding acid is what lowers TA.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
I wouldn't put it that way, but still that is essentially true. Acid lowers both PH and TA. We are limited by the fact that PH going too low will cause damage. Aeration is what allows us to raise the PH back up without also raising TA back up. Any of the normal PH increasing chemicals would also raise TA back above where it started.