Lowering TA, How long should i aerate?

ParB

Gold Supporter
Apr 26, 2020
108
SF Bay area (silicon valley)
My PH has been raising pretty quickly so i decided to lower my TA.
When i started i had TA of 160 and a PH of 8.1.

I added muratic acid in my pool until PH reached 7.0. I did this in increments, ran the pump and tested again (my journey was 7.7, 7.4, 7.0 over two days).
I was worried about putting in too much acid at once, i read that it could concentrate in a pump or on the plaster floor and cause damage.

Once i reached PH 7.0 I put bubblers into my pool to aerate the pool per the TFP article: Lower Total Alkalinity - Trouble Free Pool

I ran them for a couple of hours on Sunday and tested in the evening. PH was up to 7.2 and TA was down to 130. I felt pretty happy about that.
The pump i used conked out so i had to go and get another pump which wont arrive until thursday. I got a couple of good hours or aeration in on sunday but that was it.

I'm going to make another go at making bubbles to try to get the TA to 90 this weekend.
the PH today Tuesday is 7.3 which is unchanged from Monday, but up from sunday evening which was 7.2 (sunday mid day was 7.0).

My plan for this upcoming weekend is that on Saturday morning I'll lower the PH to 7.0-7.2 and throw the stones in to aerate.
Is there any golden rule for how long i should aerate? Is a day enough? is this a multiday endeavour?

My manifold lets me use up to 6 stones in my pool generating bubbles from a pond compressor. It will push about 16 gallon per minute (or 1 Liter per second) through those stones.

Any thoughts on the plan?
Any ideas on how long i should anticipate aerating the pool with this scheme?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,491
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
You should aerate until your pH is back to 7.8 - 8.0. Then lower your pH back to 7.2 with muriatic acid to lower your TA. Repeat until your TA is 60-70.

There is no predicting how long you need to aerate. Everybody's setup is different.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,491
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
It is very difficult to predict how long aeration will take.

How effective the aeration is depend on both the number of bubbles and their size (you want lots of small bubbles). Both of those are difficult to measure or describe, so it is difficult to compare one situation to another.

The rate of pH rise with aeration also depends on the TA. The higher the TA, the faster the pH will rise.

Extremely effective aeration will take hours, less effective aeration can take days to raise the PH.
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
2,950
Spring Valley, NY
Not sure why you need to rush the TA lowering. Treat the PH as one would do when it's at the 8.0 range, hit it with MA to bring it down to 7.2ish, then let it take its course again and rise slowly. The TA comes down some every time you lower the PH.
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
6,431
Damascus, MD
Pool Size
29000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
I went from 90 to 60 and it took 2 plus weeks running both my waterfalls 24x7. Used about 4 gallons of acid.
 

Selenap

Well-known member
May 28, 2021
243
Waynesville, NC
Pool Size
25200
Surface
Vinyl
Chlorine
Liquid Chlorine
I took my ta Fromm 180 to 100 in a week. 6 gallons of acid and continuously aerated with a sub pump. My ph never fell below 7.2. Never higher than 7.8 though. I fast tracked so I could put boric acid in it. That was all. I’m impatient that way. It’s just a matter of getting a feel for what your pool is doing when you’re doing something to it. A zillion small bubbles coming from the deep will out gas faster than big bubbles created near the surface. And find some kids to get in it and stir it up.
 

ParB

Gold Supporter
Apr 26, 2020
108
SF Bay area (silicon valley)
Thanks all, this is what I was looking for.

A rough estimate on time based on real world experiences. I want to make sure I budget my time correctly and if it's going to take many days. Given the experiences shared I think I'll route the air hoses under my pool cover so I can run it while the cover is closed at night.
 
Thread Status
Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.