We are new to pools, we had the help of a professional to install the pool and filtration system. The filter is supposed to be one of the best on the market but when we add the d.e. the filter stops working like its clogged. We have started experiencing a cloudy greenish water. We have vaccuumed every day for the last 3 days and have added 3 gallons of shock to the pool in the last 2 days with no change. We even took the filter apart and cleaned each filter individually and when we put it back together we didn't add d.e. back to it thinking that was the problem. But, from reading your forum its sounds that d.e. or maybe sand is essential. Any ideas?