And I suppose that makes me Hitler for having 1 betta, 1 snail, and 3 lemon tetras in my 5.5 gal?
I present my 5.5 gallon dungeon (the tetras maintain their sanity by singing spirituals and carving the passing days in the glass with small bits of gravel):
I think people who rant about 5 gal. tanks being "too small for fish" probably just don't have a good idea of how big they are.
A 10 gal. tank is 18.25" wide and 10.75" deep.
A 5.5 gal. tank is 16.00" wide and 8.25" deep.
So, the 10 gal. is only 14% wider. It's not a fish torture chamber.
It's weird that most people here would tell me the tank was grossly overstocked, but even fully grown I would barely be hitting the generic one fish per gallon mark.
I do think that decorations change things a lot, though. If they didn't have plants and a little corner of bubbles, it would probably be a kind of depressing little box.
People also told me that Lemon Tetras would freak out, lose their color, die, or who knows what if I didn't have at least five. Instead they've gotten much brighter color, and they're totally calm. It took me a long time to get a picture where they were actually together instead of just happily poking around the plants separately. Maybe they're just happy I rescued them from the 10 gal. that was packed with about 20 lemon tetras (and some other species of fish) in the LFS.