All, glad to find the forum here. Got a place in North California, Contra Costa area, with a large but defunct pond. I would estimate about 1800 gallons, but I'm still in the process of getting it cleaned out. Right now I'm using a sewage pump and a power washer on the pond, cleaning the sides as the water level goes down, then pumping out again. Initially it's been too thick with crap to keep a filter going, which is why I'm emptying and cleaning. Love to hear what has worked for people in the area, especially for fish.