Water req per goldfish

Just to stir up an old argument again,
I thought I'd mention this.
The current issue of "Aquarium USA 2004",
an annual "buyer's guide" type magazine usually
found at the checkout stands at PetCo, et al,
has an article about goldfish.
Among some wise pieces of info (e.g. goldfish are
_not_ for beginners, and are more challenging than
most tropicals, etc) is the recommendation that
since water quality is the #1 issue, goldfish
should be given 20-30 gallons per adult fish.

In thinking about it, I actually think this is
wise, if by adult fish you mean really good-sized
specimens, say 6"+. My 55 would be just right for
a couple of big bruisers, but can you imagine how
silly I'd have felt last year this time with only
two little 2" guys in it.... If I had it to do over
again, I like to think I'd do it that way, but I suspect
I wouldn't. But right now I've got five fairly good
sized fish (5-6") in that 55, and it does require effort to
stay on top of water quality issues.

Gunther