I guess that a lot of us (me too) have had a one or two inch goldfish in a half-gallon bowl, but they soon outgrow that. I was surprised to read on a goldfish site that goldfish can live 25 years. So if it is 2 or 3 now, think of how old you will be when it dies of old age.

That same site suggested that three or four adult goldfish, with significant weekly partial water changes, would be comfortable in a 55-gallon aquarium. I doubt that many of us think about what the needs of an adult goldfish will be. Hopefully we do better with the guppies.

And I know that you wouldn't do this, but for someone looking on, please never dump goldfish into local lakes and streams. The dumping of carp into American waters 100 years ago has been an ecological disaster. A park lake in my hometown gets so full of goldfish, that they drain it down about every 10 years and kill everything off, restock and start again. And just to prove how stupid some of us are, the authorities let southern fish farms keep these black carp and big mouth carp on the promise that they would never be allowed to get out - which of course proved to be an empty pledge with major floods in the '90s where so many ponds overflowed into the rivers. Don't know how many billions of dollars that will cost the economy.