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.Yeah, I was more concerned with whether or not what's being filtered through it would end up clogging it, rendering it less effective.
Hmm, no wonder I’ve never “needed” to backwash!25% above your starting pressure of 10 psi would be 12.5 psi, not 35 psi.