Replastered inground spa requires acid daily after 3 months.

[mmhuff]

Had my 1000 gallon inground spa replastered with white plaster the week before Thanksgiving. The temp was probably in the 40s when they finished it and they used a blow torch for a while after finishing and before adding water. I have been managing the chemistry using the Taylor 2006 test kit. Every single day the pH is above 8 when I check it and I have to add 1.6-2.8 ounces of Muriatic acid. I know it takes a while for the pH to settle down after new plaster, but it shows no sign of stabilizing and I’m beginning to wonder if there’s a problem with the new plaster. I’m starting to get a white build up on my tiles also which is possibly scale. The pH rises even more quickly if I heat the spa. I have been running the circulation pump 24/7. Water is clear. My test numbers today before adding acid:

FC 3
CC 0
PH 8+ (acid demand 2 drops)
Alkalinity 90
Calcium 450
CYA less than 30
Temp 84 F

Can this be normal or is something else possibly going on?

 

[Bperry]

Had my 1000 gallon inground spa replastered with white plaster the week before Thanksgiving. The temp was probably in the 40s when they finished it and they used a blow torch for a while after finishing and before adding water. I have been managing the chemistry using the Taylor 2006 test kit. Every single day the pH is above 8 when I check it and I have to add 1.6-2.8 ounces of Muriatic acid. I know it takes a while for the pH to settle down after new plaster, but it shows no sign of stabilizing and I’m beginning to wonder if there’s a problem with the new plaster. I’m starting to get a white build up on my tiles also which is possibly scale. The pH rises even more quickly if I heat the spa. I have been running the circulation pump 24/7. Water is clear. My test numbers today before adding acid:

FC 3
CC 0
PH 8+ (acid demand 2 drops)
Alkalinity 90
Calcium 450
CYA less than 30
Temp 84 F

Can this be normal or is something else possibly going on?

Your alkalinity is still too high which makes pH rise faster. Let it get down to 50/60 and see how things go.