I am looking after my neighbours SWG 20,000 gal plaster pool. As he is recovering from a major operation, it might take a year.
He wants to spend as little as possible on pool maintenance as funds are presently tight. I did explain that although the pH settles at 7.7 it would be better to add acid to keep it at about 7.3 to avoid iron stains which do develop over time in our pools. I did do a no drain AA treatment which worked well, using Jack's Magic Purple Stuff as the sequestrant. He does not wish to purchase additional Purple Stuff nor add acid to lower the pH from 7.7.
The current test results are as follows:
pH 7.7 (stays there - does not seem to go higher)
TA 90 (does not budge)
Borates 0 (2 dogs)
CSI + 0.04
Would moving the CH down to 250 from 400 help with the iron staining issue and perhaps calcium scale, this would give a CSI 0f - 0.16? Or is the pH at 7.3 or below the primary factor affecting staining, I believe that a lower CH also helps or is this assumption incorrect if the pH is not adjusted to 7.3 or below?
Any help would be appreciated, thank you.
Please note the specs below are for my pool not his.