We're new pool owners, never having owned a pool before. My in-laws said that, when they used to have a sand filter (they have DE now) they would add sand to it a few times a year. Our pool builder didn't say anything about this, and I'm wondering if I should be adding sand to our Pentair Triton II sand filter once in a while? If so, how do I know when it needs sand, and how do I know how much to add?
(Apologize in advance if this is a dumb question!).