- May 11, 2010
My calcium hardness has been low this year. It was at 180-200 for a few months and it has now dipped down to 140 this week. I was already concerned that it isn't between 250-350 and now it is really low after a rain has almost made the pool overflow. Should I add a calcium product from the pool store or will the 1 1/2 lbs of 73% calcium hypochlorite shock that I add every week eventually take it up? Any recommendations? I don't want plaster damage.