I've always had this problem since filling, this year I thought I would try to hit this hard right away. I drained a little less than half (12978gals) this weekend and refilled. I went from the 500's to now 400 exact! Still not happy with that number. My tap water is 160, pretty hard! What kind of problems am I going to experience leaving at 400? Not sure I really want to drain the whole pool. I ordered a complete refill kit from Dave, but I don't think the kit is the problem. I have always hard a hardness problem in my house.