"Dave Schwartz" wrote in
message ...
All of a sudden, this season, when the pump stops
running, I get a backwards
flow of water through the skimmer, bringing along
with it some diatomaceous
earth from the filter which then gets into the pool
and ends up on the
bottom. Never had this problem before. Other than
that, the system still
works fine. Any thoughts as to what's happening?

--
Dave Schwartz
Commack, NY



It sounds like the back-flow valve or flapper isn't
doing its job. Sometimes, as in a Hayward, the "valve"
is a simple piece of rubber that gets sucked down onto
the inlet if the water tries to backflow.
Do you have a see thru pump cover to see the earth
coming out of the tank? Check it when the pump stops.
If not, open it up and then open the air-release on
the filter and watch to see if water comes back from
the tank. This will lose your prime, but if it's self
priming it shouldn't matter.

Just a thought, esp if it was disassembled for
cleaning.

Pop