DE Filter Pressure Question

[impnst8]

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).

[Watermom]

I moved your post into the subscriber section so it will get priority attention but unfortunately, I'm not sure what to tell you to try. Ben is better able to help with this one than I am. Hopefully he will be by before too long. Sit tight. Shouldn't be too long.

Glad you officially joined us and thanks for the subscription. That is much appreciated!

[PoolDoc]

Is this your filter?

[impnst8]

Yes.

[PoolDoc]

Parts:

[PoolDoc]

It sounds like some of the pool water is bypassing the grids, or at least the DE on the grids. Open the filter and check for any split, cracked or missing parts, and ALSO for any part of the grids that are broken or not coated with DE. AND check for tears or splits in the membrane.

I'd focus on the upper parts, since I suspect you'd be more likely to see dirty water if the bypass were lower down.

Pay particular attention to the upper manifold (#14).

CAUTION: if you don't relieve air pressure before opening, the tank can 'explode' and hurt you!