I have a 18' x 33' AGP pool that's 5' at the deep end. I need to get a new filter/pump. I didn't open it last year for the same reason. It's been covered and has no rust or leaks. I no longer have the old filter or pump so I have no idea what size of either I need. I had a DE filter but think I'm going to go with a sand filter. Any help with this would be appreciated. thanks