A couple of years ago when I was relying on pool store knowledge, the lady who tested my water told me that I shouldn't backwash my sand filter after everytime I vacuum the pool. Her theory was that I was keeping the sand "too clean" and it needed to be "sticky" or dirty to do its job!! My filter gauge stays around 16 PSI no matter how much I was backwashing. So I backed off a bit. It's only when it starts to creep up above 16 when I now actually backwash after vacuuming using her theory. This year, we haven't had a lot of action in our pool because of farming and life in general. But we did have to replace our filter pump after a storm and I'm wondering if my lack of backwashing had anything to do with that? To backwash or not, this is my question???