PH Levels after Newly Plastered Pool

[markphin]

Thanks for the quick reply. I will get numbers posted later this week. I do keep the TA in check. In fact I had to add some TA up to bring levels back with in range last week. Thre was no special start up method used. But when they finished plastering they did a light acid wash to expose the aggregate. Perhaps that is contributing.
Thanks Again

[CarlD]

Thanks for the quick reply. I will get numbers posted later this week. I do keep the TA in check. In fact I had to add some TA up to bring levels back with in range last week. Thre was no special start up method used. But when they finished plastering they did a light acid wash to expose the aggregate. Perhaps that is contributing.
Thanks Again

I hope you realize that TA Up! is nothing more than ordinary baking soda. If it says Sodium Hydrogen Carbonate, you should know that's an alternate name for Sodium Bicarbonate....Arm&Hammer Baking Soda! And, if you use pH Up!, you'll see it's Sodium Carbonate--same thing as Arm&Hammer Washing Soda (In the yellow box in the laundry section).

[chem geek]

Also, what is the "range" you are talking about when you write "to bring levels back with in range"? Pool industry standards are NOT correct and when using hypochlorite sources of chlorine (e.g. chlorinating liquid, bleach, Cal-Hypo, lithium hypochlorite) you want your TA lower, even lower than 80 ppm if necessary to have the pH be more stable. This is because TA does not just buffer pH, but is a SOURCE of rising pH in its own right because TA is largely a measure of how over-carbonated water is compared to air.

[markphin]

The TA was 70. So I added enough to bring up to 90. I see what you are saying though. Keep the TA at lower levels and it will help control the PH. Thanks I will keep an eye on that. Things do seem to be slowing down a bit more. Over the last 5 days I've only added about 2 quarts of acid, when up to this point I was adding about a gallon a week.

[CarlD]

The lower TA should help. As the concrete cures the rising pH should end. Do you have anything like a waterfall or fountain or other water effects? They all create aeration which tends to raise pH (but doesn't raise TA--that's why we use it in our TA-lowering strategy).

[markphin]

No fountains. A spillover from the hot tub though. Yeah, I'm sure the PH will stabelize eventually. I just didn't think it would take this long. I'm hoping it stabelizes by the time I winterize in another month or so.

[CarlD]

The spillover could well be part of the reason for a rising pH, because it will aerate the water.