I have a 700 gallon pond with five gold fish. One goldfish is from an aquarium and is about 7 inches long. The other 4 are feeder goldfish that survived when I put them in my pond. About a month ago I saw baby fish and just thought they were baby goldfish. Now that they are bigger I am not so sure. They are all a dark grey with a lighter belly, and when they move a certain way they kind of flash a silver color. Could there have been eggs on some of the plants I ordered for my pond? If they are goldfish when do they turn gold?