Hi. Long time lurker, First time poster...

I have a Hayward 48 DE filter on IG, salt water pool. It's still a little cold in NJ, but have had the pool opened for about 4 weeks. The water is clear, and everything seems to be working fine, but I just noticed that the pressure on the filter isn't rising when dirty (not sure for how long as I have just backwashed each time after vacuuming). Even after vacuuming the pool (water seems clean...can't see any dirty water shooting back in pool) the pressure on the guage stays at it's usual, clean starting pressure of about 11 psi. I've backwashed several times, see dirty water and DE leave the system, but still the guage reads 11 psi. I have a 2 speed pump. so when I switch to low speed, the guage drops to about 4 psi and when off the guage falls to 0, so I don't think it's a guage problem. I've been using the same, 6 lbs of DE after each backwash. I replaced my grids with fully assembled generic grids 2 years ago, but they seem to be working fine. Ideas??

I did notice several weeks ago that at low speed, dirty water was shooting into the pool. On high speed, clear water. I disassembled the filter and hosed out the grids and filter bowl. There was a bunch of gunk in the bottom of the filter and it seemed to fix my low speed dirty water problem (I was lazy and didn't hose the grids at the start up this year).