We have had a pool for about 10 years and have done a good job in that time maintaining the water quality. This year we had a problem with algae which we solved with chlorine, algicide and flocculant. However, we now have a problem with the floc. It seems to be passing through the sand filter as the water coming from the return is discolored and the clarity of the water is not improving with filtration. but when we stop running the filter the floc will settle onto the bottom of the pool and the water will be crystal clear. The sand filter is a brand new replacement for our old one. We have never had this problem in the past when we have used floc. What do you suggest.