Had to redo the pond since last pump wore out on me over winter. Its going to take a while to clear up. I have my new pump set on a timer so it doesn't overwork itself. I live on two acres and my pond is far back, so I had to run an extension cord. I used these fairly cheap cord protector to prevent rain from damaging them . I also put tubing on the cord to the pump. Turtles get curious and sometimes they investigate with a bite, and cords and bites...you get it. I wax floors in my spare time, so as a filter medium I used stripping pads and may or may not have shredded my hands when I pushed them in the trash can. There is gravel at the bottom and pvc silicone at the end.