25gallon? get some minnows, when that guy gets to be a adult there wont be any other room for him or buddies. Go grab a 55 gallon and you can house 3 goldies. Calicos have some nice color to them, or a white/red ryukin.
25 gallons? The tank is full! Overloaded, actually. Your three-inch goldfish is producing nine inches of waste. Sixty gallons is the recommended minimum for one fancy goldfish.