DE backflow - What did I screw up?

[denhandt]

Several weeks ago, I opened the relief valve on top of the filter while the pump was turned off - the lines started gurgling and a fog of DE entered the pool through the main valve and skimmer. This had not happened before.

The backflow occured after I (1) replaced two torn DE filter elements and (2) cleaned / re-lubricated a leaking push/pull backwash valve (the leaking stopped).

I've subsequently discovered that backflow does not occur if I loosen the pump lint pot lid before opening the filter's pressure relief valve.

Of course, now I can't get the DE out of the pool....the pump runs routinely for several hours each day, and I've tried vaccuming several times, but the water remains cloudy and the pool surface remains coated with fine layer of DE.

What did I screw up?

[poolshark]

Did you ever get any sort of personal reply to this??? I have a similar problem.

[denhandt]

No replies. I re-cleaned the filter and re-introduced DE. Pool's finally clear of DE, and I'm apprehensive about releasing filter pressure to see if it happens again.

[lonestar]

Did you open this valve with the intention of cleaning the DE filter? I usually backwash the filter thoroughly before opening it to clean (as this makes it lighter.)

In the few situations I have gotten large amounts of DE into a pool where I knew the filter was not leaking DE, I leave the pump off for a day then vacuum the pool.