That's it WOW! I was at the well for almost ten years. I buy dark gray filters that have gotten slimy for some reason over the past few years without losing water pressure. The water took on an odor that warned me it was time to change the filter. Decided to try another filter (this one). I will use up the remaining gray ones and buy these from now on. When it rains heavily, the mud rises in the well and they take on a nice dark tan. jokes But no slime. I can live with it.