Lowering TA - aeration required?

stevenfex

Active member
May 1, 2021
36
orange county, ca
Pool Size
17000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool Edge-40
I installed a new Circupool edge 40 swg late summer and have had issues with it reading low salt (with 3600ppm salt), I believe because of scaling on the cell. After I clean the cell, it works fine. But I have had to clean scaling off the cell almost monthly. Doesn't sound normal.

My TA has hovered around 120. Test earlier today was 110. Water temp is unheated around 74.

CH 450
pH 7.8 (I typically lower pH to around 7.6 w/ MA when it gets near 8)
CYA 50
TC 9.5 (finally tapering down from high FC levels due to mustard algae 5-6wks ago).

My assumption to deal with SWG scaling is I need to get my 110 TA down. I Know about the drop pH + aeration method, but I'm wondering if just repeatedly dropping pH to 7.0 will also drop the TA over time?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,823
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
When you apply muriatic acid, it lowers the pH and the TA a bit as well. Aeration helps to increase the pH back to where it was but leaves the TA alone (lower). This process is required a few times until a person gets the TA down to where they need it. Remember there is no one perfect TA number, and that the key is finding a TA that compliments the pH by keeping it stable. Be sure to always use the PoolMath APP and monitor your CSI number and try to keep it slightly negative to prevent scale.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,487
Bedford, TX
Steven,

Over time, as you add MA, the TA will come down. But, for me anyway, it is a long time... Aeration allows me to drop my TA from about 120 to 50 in a couple of days...

Try it your way and see how well it works.. You can't hurt anything.

Thanks,

Jim R.
 

Bperry

Gold Supporter
Aug 20, 2020
1,070
Knoxville, TN
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
When you apply muriatic acid, it lowers the pH and the TA a bit as well. Aeration helps to increase the pH back to where it was but leaves the TA alone (lower). This process is required a few times until a person gets the TA down to where they need it. Remember there is no one perfect TA number, and that the key is finding a TA that compliments the pH by keeping it stable. Be sure to always use the PoolMath APP and monitor your CSI number and try to keep it slightly negative to prevent scale.
Yep, if scale is building up monthly tracking the CSI and keeping it negative will probably help.
 
Last edited:
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stevenfex

Active member
May 1, 2021
36
orange county, ca
Pool Size
17000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool Edge-40
Thanks everyone! Very helpful and good to know that I should be better off getting it down to 50 or so. I added some MA yesterday and did not aerate but we'll see how it works out and if it is too slow I'll probably aerate.
 

stevenfex

Active member
May 1, 2021
36
orange county, ca
Pool Size
17000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool Edge-40
Steven,

Over time, as you add MA, the TA will come down. But, for me anyway, it is a long time... Aeration allows me to drop my TA from about 120 to 50 in a couple of days...

Try it your way and see how well it works.. You can't hurt anything.

Thanks,

Jim R.
Jim I'm wondering how much MA you go through to achieve this? I've now added 1.75gal into my 17k pool, and my TA has dropped from 120 to 110.

I did "aerate" a bit after the first gallon by filling my pool an inch or so, letting the water splash into the pool. Fill water was 80-90 TA last time I checked. MA is 14.5% HCl. Does it seem right that it'll take me about 10 more gallons to reach TA 60?
 

Newdude

Gold Supporter
TFP Guide
Jun 16, 2019
11,533
NY
Does it seem right that it'll take me about 10 more gallons to reach TA 60
Each cycle drops the PH by 10. At/Under 100 it will settle where it wants to be on its own. Every pool is unique, even between neighbors. Listen to yours and let it be where it wants to be.

The same goes for PH. Anywhere is the 7s is good. As long as the CSI is in check, they are all equally good #s and a 7.2 is not ‘better’ than a 7.8.
 
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Bperry

Gold Supporter
Aug 20, 2020
1,070
Knoxville, TN
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
Jim I'm wondering how much MA you go through to achieve this? I've now added 1.75gal into my 17k pool, and my TA has dropped from 120 to 110.

I did "aerate" a bit after the first gallon by filling my pool an inch or so, letting the water splash into the pool. Fill water was 80-90 TA last time I checked. MA is 14.5% HCl. Does it seem right that it'll take me about 10 more gallons to reach TA 60?
Your MA is half strength so it’ll take twice as much as if you get the real stuff at 31%
 

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
2,487
Rancho Cucamonga, CA
Pool Size
18735
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45
Look for a local pool store in your area that sells MA in refillable gallon containers (HASA products). That MA will be 31.45% and a better value than the 14.5% sold at HD and Lowes. I pay about $4.75 per gallon in my area. Leslie's has it but they are overpriced for MA.
 

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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,487
Bedford, TX
Steven,

When I lower my TA, I constantly aerate... I test pH and TA, then add enough acid to drop the pH to 7.0 or so.. Then I do it again and again every 2 to 4 hours.. except when in bed at night..

At first the TA hardly changes at all... but, as time goes on the change in TA gets larger and larger. I only add enough acid to reduce the pH to 7.0, I don't add acid based on the TA number.

I only use full strength acid at 31.5%... I have not done this in a while and don't remember exactly how much acid I used, but I don't remember it being all that much.. I usually buy 4 gallons at a time and I don't remember having to run out and buy more.

Thanks,

Jim R.
 
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