Ph always high.

[linusb212]

Our 15,000 gallon concrete pool was just built this past winter. I've been using Trichlor pucks in a feeder to chlorinate but am switching to bleach because my cya is about where it needs to be.

My ph stays high...about 8. I can add 1/2 gallon or more of acid and it brings the ph down into the proper range and 2 days later it's back up. TA is about 80 last time I checked...which has been a few weeks.

Water is crystal clear. I don't have a heater. Is there danger of letting my ph stay at the 8 level? My test kit doesn't really show anything above 8, so that worries me, but how much higher than 8.2 or so could it really drift?

Is there anything that will feed a slow supply of acid into a pool to help maintain a nice steady ph?

 

[Butterfly]

You can read the "Start-Up New Plaster" in Pool School for some pointers.

Your pool is relatively new and will require frequent acid additions to maintain proper pH.

If you have any water features, you could turn them off which should help slow the pH rise.

 

[JasonLion]

With fresh plaster, the PH can easily go high enough to cause calcium scaling, which will mess up your wonderful new plaster surface. You really really want to keep the PH below 8.0 and below 7.8 if possible. You can go a little longer between acid additions by lowering the PH down to 7.2, instead of just 7.5, when dealing with fresh plaster.

The very rapid rise in PH with fresh plaster will slow down after three or four weeks. It then continues at a slower rate for up to a year.

 

[Guest]

What is your TA? I suspect it might also be on the high side. It needs to be lower for unstabilized chlorine like bleach than it does for stabilized chlorine.

 

[linusb212]

My TA is on the low side actually...about 70. I figure if my ph is going to run high, that it safer to run a lower TA so it will be less prone to depositing scale. Is that a correct statement?

 

[JasonLion]

Yes, keeping TA fairly low helps reduce the chances of calcium scaling.