I've been lurking around here for knowledge since we bought our house about a year ago, and it's been really valuable to help me figure out issues and develop a good maintenance routine. The Pool School is especially helpful. In any case, I did a complete drain/refill about 4 months ago (mid May) because the CH had been really high since we bought the house, and there had been white flakes in the water (which I assumed were calcium deposits) which I could never get rid of. After I did the refill, it took me a couple of weeks to get everything balanced (mainly the alkalinity), but since then the water has been clear and beautiful, and the water balance has been basically very stable except for two things:
1) I need to add 2 cups of 20 Baume acid every other day to keep the pH in range (add at 7.8, brings it down to 7.5). Is this typical, and if so, is the constant acid requirement due to the aeration from the spillover spa and the SWG? Alkalinity has been very stable at 90.
2) The calcium hardness has been increasing rapidly. The fill water CH was 270; it is now up to 460, so it has been increasing roughly 50 ppm per month. Does this make sense? The only reason I can think to explain this is evaporation, but while it has been hot this summer, I really don't understand if this alone can explain the constant CH rise.
Load is light (just a few people swimming, and mainly on weekends); otherwise the water looks great. But at this rate, I'll be back up to the previous CH levels within a year...
Latest test results from last weekend:
Thanks in advance for any help.