How to lower PH without lowering TA ?

[steviek]

Hi,

I have a new plaster pool about month old. First couple of weeks used lots of acid to lower the TA and finally got it where wanted. Took about 7 gallons of acid.

Anyhow I find myself having to add acid now just because of PH. PH creeps up to 7.7-7.8 range and every couple of days I find myself adding pint or 2 of acid. I don't mind doing this but am very worried I'll end up dropping the TA.

So how to drop the PH without dropping TA ?

FC 5.0
CC 0
TC 5.0
PH 7.7
CH 170
TA 90
CYA 40

 

[oldguy70]

Likely your pH will keeping rising for a while, adding acid will lower TA. Until your plaster fully cures, you will have to keep an eye on both pH and the TA. Finding a sweet spot on the TA will help.

 

[pooldv]

It is OK to let your TA drop down as low as 60, even 50 if you PH remains stable. If not then you can raise TA with baking soda without raising PH much.

More handy info about chems here, Pool School - Recommended Pool Chemicals

 

[atttech-2]

With our new pool walmart baking soda was a staple for the first 6 month or so. I was going through 4 pounds every 3 to 4 weeks.