Difficulty:Easy Max Growth Size: 15-25cm Temperament: Preferred Water Parameters: Temperature:22-27 degrees celsius pH Level:7.2-7.8 General Hardness: Mod- Hard Diet: herbivore despite what many aquarist feed them. foods such as Brine Shrimp and shelled peas (which are excellent for constipation). However, “meatier” types of foods should be used sparingly, and very high protein foods such as worms should be avoided altogether. The Ryukin Goldfish has a curved backbone, a fat belly and long feathery fins. It has a small, pointed mouth and the body is typically triangular in shape. There is a distinct hump on the back immediately behind the head. The Ryukin Goldfish comes in a variety of colors, including the Red/White, Calico, Red/Black and Red.All goldfish are members of the carp group and are generally quite hardy. The Ryukin Goldfish will do well in a tank of 30 gallons of water or more with a fine gravel bottom and hardy, cold water plants, as well as backyard garden ponds of 180 gallons or more. Goldfish are diggers and will scatter the fine sand onto leaves, injuring thin and less hardy plants. Roots and well-rounded river rocks are a good addition to the aquarium.