I had a new pool built which was completed this past April, 11,600 gallons, SWG with quarts aggregate plaster, small sheer decent water fall and a raised hot tub. I've been following the trouble free pool suggested chemical levels in the pool math chemical calculator. My CH hardness had been steadily rising all summer, some people told me this was probably due to the plaster curing. My question is in the pool math calculator the suggested CH levels are 350 to 450 ppm, my CH levels have balanced out at 420 ppm, is that too high even though it is in the suggested range? I have a little scaling with parts of the plaster feeling like sand paper but that may be due to at one point my CH was around 510 PPM. My chemical testing done today with my Taylor kit were FC 8, Combined Chlorine 1, TA 60, PH 7.4, CYA 30, CH 420, Salt 3000, water temp is 60. I've also been having to add acid regularly due to rising PH from plaster curing.