New pool owner here. The pool, 24ft above ground, came with my new house. Ever since I opened the pool this year the water has been cloudy. All of the chemicals are reading where they're supposed to be. I've shocked it as needed and run the pump 4 hours during the day and 4 hours at night. When I Backwash, which I've been doing frequently due the the cloudy water, the water coming out of the filter is milky colored. We've also noticed some sand in the bottom of the pool. Are these issues connected and how can I fix it? We really have no idea how to care for this thing as we've never had one before.