This was my first year using the 4820DE. What a huge difference compared to the old grossly undersized cartridge filter.
That said, when I went to close the pool this last weekend, I tried a backflush and didn't notice much debris coming as viewed through the observation window port thingamajig.
Truth be told, it was a while since my last backwash and recoating of the filter... Probably 1.5-2 months.
After the pool was closed, I opened up the filter to see all grids were covered with sludge, and non was removed during the backwash.
I pulled the grids and hosed everything off well, reassembled and all is fine.
My question... Is this normal? Is this because I didn't backflush regularly and things gummed up? My pump is pretty powerful and I thought should clear old filter media from the grids.
What should I do differently next year?