I have opened my pool several days ago and have thought 3 times now that things were starting to clear up and look better only to realize that the jets keep pumping filth BACK INTO the pool! It seems to happen at two different times. The first is when I backwash. I noticed bubbling at the closest jet and then saw earth and algae flowing out at the same time as water was going out the backwash hose. The second time seems to be when I brush the deep end by the drain. Last night I thought we had really made progress so I grabbed the brush and went around the pool. When I reached the deep end drain, tons of particles began flowing out of the jets. Horrible!
This did lead me to discover that I have been running the pump in vacuum mode even though I have not been vacuuming. In other words, all my pull was at the skimmer and none at the bottom of the pool. I don't know if this is part of the problem or not.
After I fixed this last night, I left the pump running all night. When I came out this morning, the pump was still running and the pressure was about 15 (10 when I started) but there was NO water returning to the pool through the jets. As soon as I bumped it, the jets flowed as normal.
The pump is the Hayward Perflex EC-65 from the 80's.
http://mypool.com/Help_files/Parts_Diag ... x-ec65.htm
Any help is greatly appreciated! Thank you! ---Melanie