Okay, so we have a 30 gallon tank with three Goldfish. Two that claim to be Ryukins, and one Common Goldfish. Plenty of room, but the Commoner has begun chasing the other two around, and it doesn’t look playful. I am struggling to determine if this is merely play, or the beginning of something serious. We love our .26 cent fish, we have had him for a year now, but this is starting to tick me off. Any ideas? Thanks.