Where I work, some of the admin girls have a goldfish in a tiny tank, way smaller than it should be. While I've mentioned it when they thought about adding a second fish (which I convinced them not to), they've had a bit of a "she'll be right" attitude to the one already in residence. Today they called me over to diagnose it's latest illness, which looked like white spot at first but is more likely a bacterial infection.
I'm inclined to take the fish off their hands, nurse it back to health, let it free into my pond, and suggest another species for them. Would a couple of guppies be ok in a roughly 10L aquarium? It looks kind of like the small plastic krazy crab enclosures. Any other suggestions?