Maggie's Mom wrote:
"Crono" wrote in message
...

sure, they love company.


In that case:

a) how many goldfish can a 30 gal tank hold without overcrowding?

Some say 10 gallons per fish. Start with only one then see how things go.

b) what size companion should I get for Harold? (I am worried that if
the companion is too small, Harold may actually damage it)


Who knows. Some are friendly, some are not... don't put a very small fish,
but you really don't need to put an equal sized fish. The important thing is
that you don't put "fancy" goldfishes (telescope eyes etc) with a so big
comet... just put another comet or similar goldfish. I would put a 3-4 inch
comet with different colors