I assume it is filter sand. I don't know I've never had any trouble. I do think that is what I see sitting on the bottom of the pool, in the cracks every morning - my pump runs at night. I just figured it is okay for some of the sand to come through, it gets sucked up by the pool sweep. I just thought of something - maybe I need to run the pump more. It is on a 12 hour timer right now. Should I turn off the SWG while bleach shocking? If so, why?
Thanks again,
Brad