New Spa owner here...

[PaulR]

I'll keep posting, but still wonder if it is OK to assume the CYA is at 0 from the city?

Yes. It would actually be counterproductive to have CYA in the tap water.

The TA-reduction process works really quickly in a spa because of the (usually) huge number of jets and small volume of water. Looks like you made it work really well!

I put 30ppm borates in my spa a month ago and the pH hasn't budged since (with TA 50).
--paulr

 

[Chakara]

It does seem to be working. Wife is checking pH which has sat at 7.2 since I left on Monday. The TA should be about 70.

When I return I'll probably up the TA to 80 to see if I can get the pH a bit closer to 7.5 and then once that is stable do the borates.

Thanks everyone - great resource you have going here!

-Chak

 

[Chakara]

I have a question I'm not clear on.

FC : 5
CC : 0
pH : 7.8
TA : 60
CH: 130 (from older test)
CYA: 45 (from older test)
Borates: 50 (estimated from pool calc)

The question is this - my TA seems be riding between 50 and 60 - yet my pH is staying right at 7.8. I was hesitant to lower the TA in an attempt to get the pH lower as I wasn't sure how low as safe. Pool Calc shows my current CSI @ -3. Pool Calc seems to show that if I lower my TA and thus my pH, the CSI will drop to "dangerous" levels.

I must be missing something - or maybe I'm good just the way I am?

Thanks!

-Chak

 

[PaulR]

If it's truly vinyl, a low CSI doesn't matter. Most standalone spas are fiberglass, though, and they do care somewhat. CSI will vary with pH, TA, and CH; if you lower one, you'd need to raise one of the others.
--paulr

 

[JasonLion]

You are good where you are. If PH is stable at 7.8, then don't mess with it, let it stay where it is.

 

[Chakara]

I think it is some kind of acrylic - I'll fix my profile. And thanks guys - I'll let her sit happily @ 7.8 pH.

-Chak