DE filter problem ~ PLEASSSE HELLLPPP!

I have a Pentair Fac Fab Star ST50 DE filter with a 1HP Dynamo pump. My filter has not been holding the DE and thus it ends up in the bottom of the pool. Took it apart and noticed a TINNNNYYY tear in the bottom corner of one of the grids. Everything I read says that will do it (hard to believe). Also, the bottom manifold that the grids sit in had 2 of the prong-things broken off (we bought this whole system used). So I ordered a new grid, new bottom manifold and new screws off poolcenter.com. Hubby replaced everything and we started it back up (by this time, pool was green). Alas ~ SAME THING HAPPENING. We put the DE in slowly through the skimmer (4lbs. for 10,000 gallons as recommended). The next day we took filter apart and again, there was NO DE on the grids. Only the top 2" or so of each grid was covered in green gunk. The rest of the DE sludge was sitting in the bottom of the filter (and some on the bottom of the pool). Does anyone have this filter? Does anyone have ANY suggestions? We think we lost the check valve, but not sure if this is a problem or not. The purpose of this valve says it is to prevent DE from going back into the pump (not the pool).

Also to note: flow coming into the skimmer is not strong. Filter pressure starts at 10-12 and never changes (up OR down).

Any ideas??????? :mad:

May be a problem with your multi-port valve. It may not be seated properly in filter position or spider gasket is shot.

As you just changed out the bottom manifold and replaced a grid-

1) were the slots that fit into the top manifold there and properly in place?

2) did the fabric of the grids fit tightly up to the top manifold - i.e. did you tighten them down far enough?

3) while it was apart, did you thoroughly clean the grids with a good pressure hose and chemically clean them if the water was slow to drain out of them?

4) did you check all the other grids for rips or tears?

5) have you tried putting the multiport on 'recirc' to see if the skimmer suction and return flow are better?

These are the quick things I would check if i were working on this;)

Ok, here is probably the biggest problem of all.........I don't even know if I HAVE a multi-port valve. LOL!! This filter doesn't backwash. It is a swish-n-bump kind. And I don't know what a spider gasket is. That is not one of the parts listed on the diagram I have of this filter. However, I will be investigating these two things to see if I *do* have them somewhere. Thanks!

Please read what I said HERE

If you have any questions, we'll be here to assist:) :cool: