We installed an 18' Intex pool last year, so this is the first time opening it up after winter. We have a sand filter. Do I just keep the same sand that was in it from last year, or do I need to change the sand every year?
With sand filters, you backwash them to clean all the crud out but you can wait to to that until the pressure in the filter increases to 25% above where it started.
My sand filter runs about 10psi so I only need to backwash when pressure gets to 35psi, but it’s never done that. I just backwash after we get a big rain to drain down some of the water.