We have a 16' intex that want to upgrade the pump and filter on this year. The problem is we use well water and so when I fill it I have to add mineral out and continuosly clean the cartridge filter every couple of hours for 2 days that the pump is running untill it's clear. My question is can I ever use a sand filter? Would I have to refill the sand after all the irons out? Should I just stick with a cartridge and if so what do y'all reccomend? Thanks everyone.