Pentair 2000 DE leaking into pool

[Shieldsfx]

Here's my problem:
1. I have DE leaking into the pool: It seems to be worse when the pump is off... when I keep the pump on, and brush all of the DE over a few days, it gets much better.
2. Air is getting into the filter: When I turn the pump off, there is clearly a air 'seeping' sound at the filter. It seems to be coming from the bottom of the filter. Added to this, I've noticed some dripping from the bottom but it stops after the pump is on for a while... Another symptom is this: when the pool filter turns back on, there's a serious stream of large bubbles exiting the jets for about 3-5 minutes.

My take is that the o-ring at the bottom of the filter is shot (or there is a leak in the housing itself at the bottom of the filter), and when the pump is off, this leak 'pushes' DE back into the pool. Over time (pump on/pump off) it builds up, which is why I notice more and more in the pool over several days/weeks.

My questions are:
1. Does it sound like I'm on the right path before I start taking things apart?
2. Also, I'm thinking of getting rid of this Pentair 2000 and upgrade to the Pentair Quad with poly housing, since I have a SWG pool (my sense is the old metal housing doesn't have a chance in a salt pool).

I appreciate your help!

 

[CraigMW]

It does sound like a leak from the bottom of the filter. Is this one of the SMBW versions (e.g. with the built-in backwash valve)? If so, it would be a good idea to change out those gaskets. However, I don't see how this would result in DE getting into the pool. Is this occurring via the returns?

 

[Shieldsfx]

Yes, it does have the built-in backwash valve... the air 'seeping' noise is coming from this valve at the bottom of the unit when the pump is turned off.

 

[Shieldsfx]

Anyway, I decided to replace the filter with a pentair quad 60. I'm reconfiguring the PVC for the new filter. Once complete, I'll update to let you know if this fixed the DE problem getting into the pool. I suspect the old pentair filter 2000 to be the culprit.

 

[Shieldsfx]

As an UPDATE: I installed the Pentair Quad 60 and it resolved the DE leaking into the pool problem! The old filter was clearly the culprit; it had a loud "seeping" air noise when the pump turned off, and lots of large bubbles were blown from the jets upon pump restart. The filter was obviously letting DE back into the pool during this cycle. I could have attempted to fix the older Pentair 2000 filter by changing out the bottom gasket or whatever the problem was, but I was looking for ANY reason to get rid of that old unit, as it was a real pain to clean out and it wasn't as efficient as I would have liked. The new Quad unit has cartridges AND DE, and looks much easier to open, clean and close. It's also a bit more compact so fits better in a tight pool room. The pictures below show 1) the new filter installed, and 2) a complexity I had to deal with when replacing the PVC joints in such a tight space. Note that there's extra piping which goes to the swim jet I have... the extra piping (with valves) to the swim jet from the filter is only for streaming water through the unit during the winter to prevent freezing (I leave the pool open all winter in the northeast). I also have a variable speed pump which operates on a very low rate to keep all pipes from freezing. When I use the hot tub or heat the pool during the winter, I have another "operating mode" setting for the pump. Hope this helps others as you troubleshoot your filters!