I bought one of these 30" deep by 10' diameter collapsable pools with the inflatible ring for my daughter. It has a cartridge type filter w/ 450 gallon per pump. She swam for week and half or so, then the pool sat for a few days where I would run the filter and skim the pool every day or so. Then I started to notice this very strong smell. I put some shock treatment in the water, but the smell was still there. The water was very clear and didn't look too dirty but the smell was pretty strong. So i drained the pool and when it was empty I went to pull the pool up and flip it over, the bottom side of the pool smelled just awful. Like death. The grass where the pool was laying smells a little but nothing compared to the plastic on the bottom of the pool. Should I throw the pool out or is there something I can do to save the pool? What caused this?