I've moved all my fish to my upper pond for now while trying to get my lower pond cleaned out and going. So today I went out to give them a little food and there was yet another new fish up there! That's 2 now, the first one was definitely a goldfish (white and orange) and I could never figure out where he came from (never had my fish in the upper pond before yesterday. And this new little guy appears to be black or dark grey with a light colored belly. No idea what he is. He's only about 2" long and is very hard to catch a glimpse of since the water is murky and he is dark. But, he kind of looks similar in shape and how he swims to my other goldfish. Weird. I just don't know where these guys are coming from!