ok , first off the original filter was 24in starite, 2nd filter 22.5 jacuzzi, now i have a 24 in hayward, all while using a 1hp pump.it looks like the sand that's in there is not the zeobrite i put into the sand filter. i was wondering if maybe adding some de to this filter might help. i've already tried some filter aids through the skimmer and only backwash when the pressure gets over 10lbs over normal. i've had this pool for 15 yrs now and this problem never seems to go away :-( i know these filters inside and out and have heard every excuse and story about the sand from the manufacturers and pool places. i never thought that i would have to vacuum every time after running the filter overnight but it's a must now.