First some background. Purchased this home early last summer with 12 year old pool. Had four months of use history before it was drained in preparation for replastering. Prior to replastering, the pH remained very stable, requiring the addition of MA only a couple of times over the four months.
Fast forward and I am now three months after replaster and I am adding in excess of one gallon of MA each week to keep the pH in check. I've added Borax to spread the dosing period from daily to a couple of times a week, but of course the total MA is the same.
For reference, my levels are:
FC 2.5 - 3
pH I dose down to about 7.3 when it reaches 7.8
CYA somewhere around 30-50 (that test is a bit subjective!)
I was expecting an increase in acid demand for the first year, but this amount has surprised me. Is this normal for a 15k gallon pool. Can I anticipate the acid demand beginning to taper some number of months after new plaster.
As a side note, it appears that the pool calculator (which I love) does not account for Borates in the calculation of MA dosing to adjust pH.