Why bother aerating pool to raise pH?

[tomfrh]

Following on from my TA threads, I recently added acid to reduce the TA down from 200 to ~130.

I dropped it down in three goes. The pH fell to ~6.8 each time, but rebounded to ~7.2 quite quickly (less than a day) without any aeration.

It made me wonder why people bother with aeration?

 

[Dirk]

Because not everyone's pool has that kind of pH rebound. So aeration is faster for some of us.

Are you watching your CSI as you manipulate the pH? The common wisdom I've read here is to keep your pH in the 7s. Lower can create a condition in your water that is not so friendly to your pool finish. Doesn't happen overnight, of course. But you can move your TA without going lower than the recommended pH7.2. I was able to, anyway.

Also, it was my experience (and I think I remember reading about it here), that TA moves down pretty quickly from that high up. But as you get closer to the target level, it takes more "coercing."

 

[cfherrman]

If you have high ta fill water, then you have to so you get ahead of the ta. If you have time one day and want to set your ta.

 

[ramsfan]

Because not everyone's pool has that kind of pH rebound. So aeration is faster for some of us.

Are you watching your CSI as you manipulate the pH? The common wisdom I've read here is to keep your pH in the 7s. Lower can create a condition in your water that is not so friendly to your pool finish. Doesn't happen overnight, of course. But you can move your TA without going lower than the recommended pH7.2. I was able to, anyway.

Also, it was my experience (and I think I remember reading about it here), that TA moves down pretty quickly from that high up. But as you get closer to the target level, it takes more "coercing."

This has definitely been my experience, and I have good data from my hot tub fresh fills. Our TA from our tap is around 180, and my target for the hot tub is 50-60, and so I drop pH to 7.2 by adding acid and running the jets. Within 10-15 minutes the pH rises to 8 or so, I drop again.... It seems like it is pretty easy to drop from 180 to 150 to 120 to 90, and then it gets progressively slower to get from 70 to 60.

 

[Dodger]

I don't go lower than 7.2, and if my CSI is still > -0.5 with that pH, I'm less concerned about accelerating the pH rise and just enjoy the extra couple of days between MA additions. Win win.

If a pH of 7.2 puts CSI <-0.5, then I'll aerate at least until CSI gets to -0.5.

 

[Richard320]

Because as a general rule, pool owners are impatient.

 

[tomfrh]

Ok, got it!