GUPPIES-- Will this work? ALSO-- BETTA

[darkfalz]

Sponge filters are good for Bettas. Only thing is my boys don't nest when there is any surface disturbance, which is a bit sad because I miss seeing those nests.

[emc7]

Are killies air breathers?

I don't think so, there are just very small fishes. AKA http://www.aka.org/aka/modules/content/index.php?id=2 recommends aeration or filtration, but a filter might be a piece of filter floss or sponge on a little tube with a an air line. These are beautiful fish that can breed in 2.5 gallon tanks and have their fry raised in plastic shoe boxes. Killie breeders often do 100% water changes rather than cycling such small tanks. Drawbacks of killies: they jump, many are so small they must have live food, Many (like the mud puddle ones) have a short life spans (months). Advantages: beutiful color, don't need much space, can buy eggs through the mail.

[TessaAndFishies]

They aren't really that small. I saw these green ones that were about 2 inches.