The tank is quite large, there is lots of room. My two goldfish a relativley small. They are the only fish in the tank, and they are definatly not the fancy goldfish tpye. The water could have something to do with it, but i clean the tank reguarly and make sure that before i put the fish in the water is room temperature (i leave it out overnight)
still a mystery
soter
shake a paw for those not so fortunate