Hayward still sells a bump style DE filter, I just bought one a couple of years ago, works great for me ( model EC-75) . The old ones had a bump knob like handle, the current ones use a lever arm handle. My understanding is it knocks most of the DE off the fingers and then when you turn the water back on the fingers are recoated with the DE in a fresh orientation somewhat refreshing its ability to filter. The only potential problem I see with this design is the finger tubes, and the fact that replacement tubes seem to sell for almost as much as the entire filter assemble. (I suspect Hayward as a higher markup percentage on parts than on compete products). From what I have read online much of the problems people have with these types of filters stems from not following the directions, and not bump cleaning or DE replacement when needed causing pressure to build up too much and blow out the fingers.
Ike
p.s. Mine shipped with a pressure gauge that has a pair of turnable indicator needles, one reg one green 10 PSI apart, you set it
with the first needle at your base pressure after fresh coating, when the pressure rises to the second needle you know when to bump. The included instruction manual just shows a standard pressure gauge and notes to bump when you have 10 psi rise over base pressure. I guess this is part of Hayward's way of making the operation easier, seems like a good idea to me, better would be an electronic pressure transducer with warning lights to tell when to bump and when to replace DE because bumping was no longer lowering pressure enough, but I guess a little bit plastic is cheaper..