I was changing the media filter pads on the top of the pond waterfall today as they were very slimy greenish & black colors. Seems like they are getting that way every couple of days now. The basket at the pump gets full and slimy as well. Anyway as I was hosing the dirty filter pads off I noticed for the first time many small brown leeches attached to the pads. I mean ATTACHED to the pads. The little suckers did not want to let go. They were all sizes from real tiny to small night crawler sizes. Does anyone have any adeas on what to do about the situation. I didn't have them at all last year and this year up to today. My wife checked on another site and someone said that the fish eat them. YUCK. Thanks for any info someone might have.