I did a refill a year ago. My calcium Harness is now 530. I just looked back at my excel file and my first CH after refill was 220. I just looked up the city water quality report and it says 114 avg ground water and 76 average for MWD water. There is a well 1/4 of a mile away so I am guessing I get mainly well water. The pool was replastered by the previous owner in oct 99. We have been here since Aug 2000. The first 10 years or so used Trichlor and then switched to Cal Hypo. At the end I was using Pool perfect and no more phos. After the last refill the pool has had liquid chlorine mainly from Sam's Club Cloriox but Leslies Liquid chlorine when it was on sale. I use Leslies Muratic Acid. Last year I did use 50ppm borate at startup. I did try once the pool Pill liquid pool cover after my solar cover started leaving its round things in the pool. I had the pool covered except for when in use during the drought until late fall when I threw it out. $200 for a cover that lasts 15 months does not seem worth it unless we go back on strict water restrictions again. I have gone from having to clean my filter every 6 weeks to I am about to clean it for the first time since July. The pool has not been Acid washed. Do I need to do an acid wash to get the calcium hardness in control rather than just dumping and refilling the pool? I am wondering if the calcium harness is from calcium buildup on the plaster. It just seems having to dump and refill in a year is a bit often.