Salt water pools are compatible with d.e. filters, so you should be fine. As to the sand filter question, typically the smaller sand filters sold with pumps are for above ground pools, and the stand alone sand filter of 20″ or larger, either top mount or side mount are used on inground pools. The size of the pool is a factor on sizing of a sand filter, as is the size and hp of the pool pump, and the size of the plumbing.