Blow-By in DE Filter

[CarlD]

Sounds like it may be time for a new and BIGGER filter or
an impeller on your pump that has a slightly lower flow rate.

Sounds like your filter is succumbing to the too-big pump syndrome.

Or it could just have some worn-out replaceable parts.

[StevenHB]

Carl, what makes you think that the pump is oversized relative to the filter?

I have replaced the pump motor (1 1/2 hp before and after) and I once had to glue the impeller back together.

I've owned the pool since 1999, so the equipment is more than 10 years old (I don't know when it was built). What's the expected lifetime of the various components?

[CarlD]

Operative word is MAY be oversized--you are getting blowback. That means something's broken, something's too low, or something's dealing with too much flow.

Life expectancy is of course determined by how much stress an object is under.

[StevenHB]

I disassembled the multi-port valve yesterday and discovered that one of the "legs" of the spider gasket had come loose. I dried it out using a hairdryer on low, and crazy-glued the leg back in place (only getting my fingers stuck a little).

The jury's out as to whether this will solve the blow-by problem, but I'm optimistic as the leg in question was between the outlet of the pump and the return line.