Unable to balance water in 1500 Gallon spa w/ new plaster

[anthonycasta]

Hello All ....

I have about a 1500 gallon IG spa with plaster that is 2 weeks old now ... I can't seem to keep the PH down .. If I start in the morning and take a reading I usually get a reading of about 8.2 - 9.0 ... After I add some acid and let it circulate for about 2 hours the reading is about 6.8 ... By the afternoon the reading is perfect about 7.6, however, the next morning it is right back at 8.2 or higher ....

I just started adding chlorine at the direction of my pool guy that did the plaster. I am having the same problem with that, in the morn there is no chlorine after I add some by the end of the day it is perfect, and the next morn is all gone ....

I have been brushing between 2 and 3 times daily. Am I doing something wrong, or is this typical of new plaster? ...

Thx in advance

 

[mas985]

Yes, high PH rise is typical with plaster although it is probably worse for a spa (less volume). Just keep on top of it and do an acid dose at night so you can start the night off at 6.8. That way it won't get too high by morning.

As for chlorine, if you are adding it at night and it is gone in the morning, then that is probably due to some algae in the water and a shock is in order. If it is getting burned off during the day, then low CYA is probably the reason.