We just purchased a house with an inground, vinyl pool, pentair fns DE filter, about 24,000 gallons. It was a green swamp and I followed the advice on this forum to get it up and running. Just figured out that each time I backwash my DE filter, it is backing up into the shower and around the base of my toilet in my master bathroom. Not good.... Anyone ever have this occur? Is there a blockage in the line somewhere or is the plumbing routed wrong. The person we purchased the house from was a "flipper" and wasn't maintaining the pool. He actually offered to just fill the thing in at his cost. Do I call a pool company to come out or a regular plumber? Yikes...newbie was not expecting this. At least the pool is now blue and clear. As for my carpet in my bedroom (along the bathroom wall), it is drying with some fan assistance. Thankfully the bathroom is tile, right?