TA has not moved down much after lowering pH

[isabelo]

I've lowered the pH twice now from ~7.5 ppm to ~7.1 ppm but TA still hovers and registers ~110 ppm. Is there something else I can do to lower the TA?

 

[RobbieH]

Let it get up to higher, maybe 7.6-7.8, then shoot for 7.2. It may take a while to budge.

Are you having pH swings? Is that why you are adjusting TA?

 

[duraleigh]

You really do not lower TA with acid alone. You must do it with acid/aeration. There is an article in Pool School that will walk you through the steps and your TA will stay down.

 

[isabelo]

Let it get up to higher, maybe 7.6-7.8, then shoot for 7.2. It may take a while to budge.

Are you having pH swings? Is that why you are adjusting TA?

You really do not lower TA with acid alone. You must do it with acid/aeration. There is an article in Pool School that will walk you through the steps and your TA will stay down.

RobbieH - No, my pH hovers around 7.5 - 7.7 pH and only when it gets to 7.8 ppm in a couple to 3 weeks that I pull it down to ~7.5 ppm again.

duraleigh - Yes, I lower down the pH from ~7.7/7.5 ppm to ~7.1/7.0 ppm then I make sure the return jets are pointed upwards to break the water surface for the rest of the day when the pump/circulation is on (I had done this scenario twice already). I also had the kids swim the other day (when we had 92degF in San Ramon) for ~ 3 hours to augment the pH rise.

 

[RobbieH]

Will your pH stabilize at 7.8? Some do.

 

[Texas Splash]

isabelo, if you are still struggling because the TA just doesn't seem to want to go lower than 110, then try dropping your pH to about 7.0. Just that extra "dip" in pH is what it took another reader for his TA to finally break that barrier where it was stuck at about 100. Once he lowered the pH to 7.0, the TA began to drop again, and of course the aeration raised the pH right back where it needed to be.

 

[isabelo]

Will your pH stabilize at 7.8? Some do.

I've have not left it at 7.8 ppm long enough to see if it rises beyond that point. But usually, it goes from ~7.5 ppm to 7.8 ppm in a couple to three weeks, maybe even a month so I thought that is stable enough?

 

[RobbieH]

That's up to you. That's a pretty long time compared to mine.

 

[isabelo]

isabelo, if you are still struggling because the TA just doesn't seem to want to go lower than 110, then try dropping your pH to about 7.0. Just that extra "dip" in pH is what it took another reader for his TA to finally break that barrier where it was stuck at about 100. Once he lowered the pH to 7.0, the TA began to drop again, and of course the aeration raised the pH right back where it needed to be.

I think I targeted pH to 7.0 ppm during my first try a week ago, then I lowered it to 7.1 ppm last Monday. But yes, I'll target for pH to 7.0 ppm again next Monday. We are expecting some rain (most probably drizzle if that) tomorrow, so that might help augment the pH rise in the weekend. Thanks.

- - - Updated - - -

That's up to you. That's a pretty long time compared to mine.

Thanks for the help, RobbieH!

 

[isabelo]

Update - Just got my TA down to 80 ppm, it took about a two weeks process, but it worked. The trick is just what RobbieH suggested - get pH to as high as possible (7.8) then aim for lowering it down to 7.2 (or 7.0 in my case), then aerate (just like what Duraleigh said). The negative to this "acid/aerate" process is I had to consume a lot more Liquid Bleach, as you would understand - I have an automatic cover but had to open it up a lot for the aeration process to do it's thing. Thanks...

 

[Texas Splash]

Glad you were able to make progress.

 

[isabelo]

Glad you were able to make progress.

Thanks to you too, Texas Splash!!!