It may be better to start your own thread on this so as not to fill the OP's thread with questions specific to your situation.
How often are you checking the pH? With your ever rising TA and pH, checking every other day for now would be good. We have had high temps and low humidity - both of which add to the evaporation and need to add water. In looking at your
PoolMath logs for the past 2 months, it looks like you allow your pH to get to 8.2 or so before lowering it. Given your other reported test results, that is helping to increase the scaling.
Keep the CSI between 0.00 and -0.30, which will help keep the scaling down. How much scale buildup are you getting in the SWG? If the pool waterline is scaling up, the SWG probably is too.
The waterfall issue may just be efflorescence and not actually scale buildup. Post pics of the waterfall and tile line buildup.
Do you have a water softener and is it plumbed to your autofill?
What strength MA are you using and where are you getting it from?
As to how much acid it takes - that will depend on your pool volume, TA and starting pH. In my 12,000 gallon pool, I use about 4-6 cups over the course of a week. I usually add acid twice weekly now. With my CH at 550, softened fill water TA of 110 and CH <50, a pH in the 7.5-7.7 range seems to work well. With your CH of 750 and about the same fill water TA, you would need a lower pH to keep CSI in the range mentioned. You have to be pro-active in this. Don't just let pH rise to to 8.2 before taking action.
