I have a 24 foot above ground pool with a Hayward D.E. filter. When we opened the pool 5 days ago the water was a little green as it appeared we had a hole in our winter cover. Since then I can not get the filter to maintain proper pressure for more than a couple of hours as it's running high and the return jet to the pool is very low. I have taken the filter apart several times and washed and cleaned the fingers as well as soaking them one time for 24 hours in a mix of water and muratic acid. I have also back washed numerous times as well as bumped the filter handle often as needed. When I cleaned the fingers last night it was the worst as they were actually green and they hadn't been like that before but I thought maybe that had to do with the cleaning and then a short soak in dawn detergent followed by the 24 hour soak in muratic acid that maybe made the fingers preform better. At this point I don'y know what to do next as it starts out running great with the correct pressure showing on the gauge and a very powerful return jet to the pool but with 2 1/2 hours or so the pressure on the gauge is up and the water to the pool jet has decreased alot. Any help would be greatly appreciated.