I have a 24 foot round pool with a Hayward D.E. filter with a 1 h.p. motor. We had the pool since 1988 and this is the original filter. The motor has been replaced once or twice but we've really had no problems to speak of. This year we opened the pool and it was quite green and we can't seem to get our filter working properly. When it was first started it was fine but as it ran for a short period the return jet started to get weak and I figured same as previous years it was from the dirty water being filtered, so I back washed it. Again at startup and for a short period maybe 1 hour it was fine and then got week again. So the last couple days have been spent bumpinfg the filter frequently as that only works for maybe a half hour and also back washing it several times which works for an hour or so. Finally took everything apart and cleaned the fingers and everything was good for 2 to 2 1/2 hours and then back to the weak return jet again. I've heard about people soaking the fingers in dishwasher detergent for several hours and then in muriatic acid. Is this something I should try or is there something else I should be looking at?