Pet Forum / Aquaria / Goldfish / August 2004

GF are big eaters and therefore big poopers. The standard recommendation is
10 gallons per GF or 3 gallons per inch of fish. So 4 2" GF would give you
24 gallons. The 40 gallon number is there because GF grow very quicly, so
they won't be 2" for long.

I have five GF in a 55 gallon tank and it is barely adequate. But the one
fish is more than 2" deep (not long) and the rest are all medium to small.

Yes, overstocked you are! I keep 4 (a good sized oranda and three
medium size deep bodied ryunkin/fantail types)  in a 75 gallon tank
and I consider that crowded. Opinions vary, but I've read anything
from 10 gallons (which I consider to be bare minimum) to 30 to 40
gallons per goldfish.

In this case, more is always better. A hex tank doesn't have as much
surface area either, so you may be short on that too. Surface area is
important for gas exchange, read getting the bad gasses out, and
oxygen in.

You could keep a few small (at adult size) tropicals in that hex. Do
your goldfish a favor and get them a 55 gallon tank! It's that or you
will probably loose some. Or you will wind up doing the "step up"
method and buy ever larger tanks for the goldfish. It's a myth that
they will only grow to their tank size. The reality is that they will
be stunted because of their tank size.

You wouldn't jam a cat or dog into a small pet carrier for the rest of
it's life would you? In essence that is what the 15 gallon hex is to
the goldfish.

Sorry to be so blunt.

Lilly

They grow to be very large. A small tank will not curb thier growth. It
will cause harm and early death due to waste build up. They need lots of
room. Some say 20 gallon a goldfish. And the platy will have problems
with the goldfish. They should not be in the same tank. If the goldfish
are small, this might be a great time to shop for a larger tank and you
can keep platys in the 15 gallon. Or If you don't want the larger tank,
you can bring the goldfish in to a petstore and get a few more platys.

Kay