DE coming out of drains when pump shuts off.

[timthek]

When my pump shuts off, it seems like water is backflowing from the filter. I see the filter basket water gets cloudy/white and see a ring of DE appear around the pool drain.
Is there supposed to be a check valve somewhere that failed, or is there maybe an air leak somewhere allowing the water to drain back down?

 

[mknauss]

This typically means air pressure is building in your filter, and possibly your filter is quite dirty. What is the filter pressure now versus clean? Always clean the filter when the pressure rises 25% over clean.

If the bleed of water is very slow, then you may have a slight leak at the filter gasket or some other item on the pressure side that is allowing air in the system when it is off.

 

[timthek]

Could it be a result of too much DE? I lost count when re-filling and may have added 1-2 extra scoops.
Pressure seems good, I may vacuum and backwash just in case.

Also, I think there is a small leak in one of the PVC connections just after the pump.

 

[JamesW]

An air leak at the filter or after the filter will cause the problem.

I recommend a check valve between the pump and filter for every de filter.