DE in pool - can't figure out the problem

[poolnovice1]

So every time the filter is cleaned or backwashed, I end up with a pound or two of DE in my robot cleaner for a few weeks and then it gradually stops.

The pool tech said he's checked the grids multiple times and he does not see a tear.

The filter O ring is fairly new and I have a brand new pool pump.

The DE seems to be coming out of the return jets.

The pool tech says this is normal but I know it is not because I didn't have this problem before. Any idea on what I should check next?

 

[JamesW]

Do you have a picture of the system?

 

[poolnovice1]

Here's a picture of the system.

 

[JamesW]

I would install a check valve between the pump and the filter.

Also, check the grids really well and check the internal air bleeder screen.