PH and Alk ?'s

Hi

I have 26800 gallon, SWG vinyl pool. Testing at pool store readings are

PH 6.9
TA 73
and Total Hardiness 86

How much Borax do I need?
and Baking soda?
and how do I raise the Hardiness?

Thanks So much

I would start with about 2-3 cups of Borax through the skimmer, give it a couple of hours to dissolve, then test again. Really, the lower the pH the better as long as it's above 7.0, so you don't need to adjust too far. Besides, when you add your baking soda (I'd say start with about 1/2 box), your pH will increase very slightly when your TA goes up.

You can raise the hardness by using calcium flakes, or by using cal-hypo when you shock--but you really don't need to raise it with a vinyl pool.

Janet