This is the 3rd year i can't seem to get the sand out of my pool. We tried repairing what we thought was a crack in our sand filter, and then this year, we replaced the whole filter. STILL have sand in the pool. We have removed all the sand by vacuuming out to the sewer so it didn't go back through the system, and it keeps showing up. At this point, I may just want to convert to a cartridge. Does anyone know what the issue could be?