control pH or CSI with new plaster

[senex]

Hi all, I have a plaster pH question that I don't see addressed in the wiki pages.

I just got replastered. Pool builder didn't say much about water chemistry: just that pH will run high for a while, and to bring pH back to about 7.8 every 3-4 days.

CH 100
TA 100
pH 8+
FC 3
CYA 30

My question is whether to target a specific pH in the 7s or to target the CSI. (In the forum I've seen notes about keeping CSI above zero with new plaster).

The trouble is that my water temp is 60F, so according to my Taylor Test Kit wheel, keeping the CSI positive requires a pH of 8.2 or higher. So, do I keep pH at 7.8 (which makes CSI negative), or keep CSI above zero (which requires pH well above 8)?

Also, the pH will drift above 8 within one day of adding acid. Should I add daily, or is that overkill (or worse, will that somehow leach out calcium from the plaster)?

Thanks.

 

[mas985]

With plaster, CSI will be important. Especially during start up. Have you read this:

Plaster Start-Up Guides - Further Reading

www.troublefreepool.com

 

[PoolGate]

Hi all, I have a plaster pH question that I don't see addressed in the wiki pages.

I just got replastered. Pool builder didn't say much about water chemistry: just that pH will run high for a while, and to bring pH back to about 7.8 every 3-4 days.

CH 100
TA 100
pH 8+
FC 3
CYA 30

My question is whether to target a specific pH in the 7s or to target the CSI. (In the forum I've seen notes about keeping CSI above zero with new plaster).

The trouble is that my water temp is 60F, so according to my Taylor Test Kit wheel, keeping the CSI positive requires a pH of 8.2 or higher. So, do I keep pH at 7.8 (which makes CSI negative), or keep CSI above zero (which requires pH well above 8)?

Also, the pH will drift above 8 within one day of adding acid. Should I add daily, or is that overkill (or worse, will that somehow leach out calcium from the plaster)?

Thanks.

Your CH is very low. It should be up around 300 with a plaster pool. CSI is very important that is the number to target. CYA is also low.

Pool Care Basics

 

[Bperry]

Hi all, I have a plaster pH question that I don't see addressed in the wiki pages.

I just got replastered. Pool builder didn't say much about water chemistry: just that pH will run high for a while, and to bring pH back to about 7.8 every 3-4 days.

CH 100
TA 100
pH 8+
FC 3
CYA 30

My question is whether to target a specific pH in the 7s or to target the CSI. (In the forum I've seen notes about keeping CSI above zero with new plaster).

The trouble is that my water temp is 60F, so according to my Taylor Test Kit wheel, keeping the CSI positive requires a pH of 8.2 or higher. So, do I keep pH at 7.8 (which makes CSI negative), or keep CSI above zero (which requires pH well above 8)?

Also, the pH will drift above 8 within one day of adding acid. Should I add daily, or is that overkill (or worse, will that somehow leach out calcium from the plaster)?

Thanks.

Yep, calcium is too low for newly replastered pool. Most of the articles I’ve read say keep it over 250ppm.