How aggressive should I be to get TA below 100? Aeration hacks?

[Steve-D]

This is our first season managing a new plaster SWG pool opened in early May. I was slow to get CYA close to TFP acceptable target levels but now it's up to 60. We're still "learning the pool" and have been successful at keeping FC between 4.0 an 8.0 by adjusting the SWG % with the pump running basically 24x7. On days when the pool is not in use it is generally covered with a medium thickness plastic solar cover (so some minimal protection from UV).

TA has been stubbornly stable @ 100 and we've only once managed to get it down to 90 with a recent MA treatment that brought pH down from 8.0 to 7.0 and TA from 110 to 90. pH has since climbed to 7.4 and now TA is back at 100. In these last 2 months TA has only once gone above 100 so my question is how aggressive do I need to be to bring TA down further? 90 oz of 20% MA took pH down from 8.0 to 7.0 and TA from 110 to 90 so I'm guessing that for me to bring down TA meaningfully using MA its going to push pH down to 6.x levels and I don't know that I want to do that in part because I haven't yet figured out a way to effectively use aeration to raise pH.

My returns don't aim like in our old ABG pool so I can't force flow up to the surface and I don't have a fountain or sump pump either that would make aeration easy to do. I do have a tiny, cheap shop vac with a very short hose I might be able to use running it backwards into the pool but even if that works it's going to be annoyingly loud. I could connect my Polaris 280 with the booster pump off and set it on the steps with the tail looped through the handrail so it sprays back into the pool...does that risk damaging the cleaner?

Suggestions?

 

[CuckooChris]

I'm gonna say your TA is fine and just watch and adjust the PH with MA. When PH gets near 8, lower it to 7.2ish.

 

[Texas Splash]

so my question is how aggressive do I need to be to bring TA down further?

Not at all really as long as your pH isn't rising exceptionally fast. If you can reasonably control your pH with some acid once a week or so, the TA is fine. If the pH shoots-up like a rocket after a day or two, then I'd take action on the TA.

 

[Steve-D]

Thank you both @CuckooChris & @Texas Splash.
MA treatment was on 6/24 so its taken about 1 week to move pH from 7.0 to 7.4 and TA from 90 to 100 so you are probably right that I don't need to obsess over it. This level of pool maintenance is new to us and a lot of $$ went into getting here so we want to treat it right and start off with good habits. Once I figure out a way to aerate efficiently that jives with "wife acceptance factor" aesthetics I'll see what I can to to gradually bring TA to a baseline where periodic MA treatment for pH when it hits 8.0 is all it needs.

I found some interesting hacks on the Aeration - Further Reading page and will see what I can put together. I will try to get my hands on an aftermarket QuickConnect adapter like for the Polaris...I'm sure that I could slap something together with one of those that my wife can live with.

 

[ajw22]

What is the pH and TA of your fill water?

TA only goes up due to a testing error, adding a chemical that raises TA, or adding higher TA fill water.

pH will rise naturally to reach an equilibrium and takes no external influence to rise.

 

[Steve-D]

What is the pH and TA of your fill water?

TA only goes up due to a testing error, adding a chemical that raises TA, or adding higher TA fill water.

pH will rise naturally to reach an equilibrium and takes no external influence to rise.

I'll have to get back on that...I did test my fill (well) water once but can't find any written notes for it. I know that CH was 230 but I don't recall if I tested for anything else.

Interesting that you ask...I overfilled by 2 inches on 6/21 when it had gotten low so I had to correct and drain the excess which would have been an exchange of about 600 gallons. TA went from 100 to 110 3 days later . The only other "fill" water since then was about 0.5" of rain this week which I'm estimating was about 160 gallons. It doesn't seem like that would be enough to move the needle either way, though. I've never added anything to specifically raise pH (or TA) and my testing for TA has been very consistent...if I made an error I would have expected to see it as a one off from one day to the next and not as a new baseline.

[edit] TA at the hose (well water) came in at 90.
[edit 2] pH at the hose (well water) reads slightly below 7.0...more specific color comparison is not available with my R-0004 test. ALSO...this is just top-off fill water. Water was trucked in for the original filling of the pool itself and I did not take a sample at the time for testing.

 

[Steve-D]

OK...so MAYBE I had some TA testing errors/irregularities..
In the last 2 days my TA reading was again back down to 90 even as pH has crept up to 7.6. I've recently switched to a new batch of reagents so it is possible that the differences may be explained there.

I wasn't aware that TA did not "naturally" rise as pH rises. The pages here re managing pH and TA say that aeration is the only way to raise pH without also raising TA so I just assumed that TA naturally rose alongside pH. Time will tell.