Start-up with Quartzscape

[zz28zz]

Thx Carl.
I wasn't sure abt chlorinating with such a low Ph so I held off. I assume the Cal-Hypo powder needs to be dissolved with water before going in the pool. From what I heard, the plaster is especially susceptible to chems while it's curing. In regards to bringing the Ph back up, is borax better than soda ash. If so why? Roughly how much borax would I need?

Thx for the reply. I need the input.
JC

[BigDave]

Soda Ash will raise pH and Alkalinity. Borax has a much smaller effect on Alkalinity - TA of 140 is fine.

CarlD is right, you need chlorine and calcium.

[zz28zz]

Playing with the pool calculator I was able to determine approx what pH my pool is currently at by knowing the pre pH, amount of acid introduced and the pool capacity. Looks like I will need approx 17 lbs of borax.

In regards to CH, my pool was filled with soft city water, but will be maintained with very hard well water. Should I try to keep the CH as low as I can get away with? Seems like it will only climb over time. In the past, I have had major scaling issues and pH is constantly need to be lowered. In the summer I add 1 gal of acid every 2 weeks. I did have a small leak at the pump until just recently, so that explains some of it.

[BigDave]

Don't add all that borax at once, you don't want to overshoot. pH change is very difficult to calculate and non-linear. Add a couple boxes, let it mix for a couple hours, measure pH, dose half as much, ... repeat as necessary. It's fine if you want to use the calc as a range for purchasing the borax. You can add borax s-l-o-w-l-y through the skimmer, it will form a hard plug if you add it too fast. Break up any chunks as you go.

The water will leech calcium from your new plaster, I'd get CH up to at least 200.

[CarlD]

As BD said, you need at least 200ppm of CH. To answer your question that is the lowest CH you "can get away with".

BD is also telling you a basic rule of ours: Always add LESS than you think you need because you can always add more.

Except for chlorine. Too little is always trouble. Too much rarely is.

[zz28zz]

Picked-up 4 boxes of borax, 3 gallons of bleach and a couple 4lb containers of CYA. Added 1 gallon of bleach and swept the pool. Tried to dilute the CYA in a 5 gallon buck, but apparently I bought the wrong kind. It's been in a bucket of water for over an hr and doesn't look like it has dissolved at all. Guess it will have to go in the skimmer once the pump is going.
Tomorrow, after work, I'll plan on adding 2 boxes of borax (by diluting in bucket), then half dose as you guys mentioned. I want to hold off restarting the pump till the pH was at 7 or more. Hopefully that will happen tomorrow night. I'll also try and pick-up the Cal-Hypo powder at the pool store on the way home.
I'm assuming that if the CYA goes in the skimmer I shouldn't put borax in the skimmer too.

[BigDave]

CYA dissolves very slowly. I wouldn't put it in a DE filter, maybe it's OK but those grids look pretty fragile to me. You can put in in an old sock and hang that in front of a return. It'll take a few days to a week to dissolve completely.

Borax is one of the only chems you can safely add with others - but to be safe it's usually a bad idea to let dry chems touch each other. It will dissolve much more quickly than CYA as long as you prevent it from clumping - if it forms rocks they take a while to dissolve.

[CarlD]

There is a liquid CYA product sold that gets into the water far quicker, but it's very expensive. And I don't know how well it works.