check with manufacturer of tank.

dont even think about other tropical fish. they cannot stand as dirty as goldfish
are. your tank is too small for anything else. also, GF will eat anything fits in
the mouth. they will eat small fish. Ingrid

On Mon, 18 Feb 2008 01:22:18 -0500, (L u) wrote:

my goldfish? I know if I add any other kind of fish, they will need a
heater.
But, is a heater safe for an acrylic tank?