When I opened my pool I used flock. When my filter is on it spits brown dirt back into the pool. I have to fill my pool every day to vacuum to wast for over 2 weeks. last year I had new sand, this year I cleaned the filter, changed the washer and replaced the rubber in the filter to make sure the water is not flowing over. My father-in is having the same problem after he used flock, so I am assuming it has to do with the flock?