(01-25-2013, 12:47 AM)scotty Wrote: he keeps out growing all his tanks so every time he grows a little bit we buy a new tank for him. I have heard people say that a goldfish will only grow as big as it's tank.
I guess you have learned it first hand that the rumor was false.
The reality is that the fish don't stop growing just because the tank is too small.
I avoid to get goldfish because they are messy fish. They eat too much and produce a lot of waste. Can't get many of them either because goldfish need large tanks to begin with. When we get a fish tank, we should always get a tank according to the fish's full adult size rather than their current size. Invest money in bigger and bigger tanks every once in a while is going to cost more in the long run than just invest once on a big tank in the first place.
Common goldfish needs 40+ gallons of water each, while fancy goldfish needs minimal 20 gallons of water each. I would hardly call them truly "big" tank, just fairly bigger than the average size beginner aquariums.
Don't worry about goldfish being lonely. They aren't school fish, there is no need to have more than one if your tank isn't big enough to house them. If you get school fish like Tetra or Rasboras, then it is required to get minimal 5~6 for each group.