White Cloud Mountain Minnow (Tanichthys albonubes)

The white cloud mountain minnow (WCMM) is a subtropical fish that prefers lower temperatures than most tropical fish. Topping out at around 1.5'', they are a fun shoaling species to watch in a tank of 20 gallons or more. Mine tend to shoal only when nervous; they're usually spread out through the tank. WCMM's come in regular and long-finned varieties. I think there's also an albino form available. I have the long-finned ones and they're stunning when they display to each other, which happens once in awhile. Feeding these minnows is easy. They accept small flakes and frozen brine/mysis shrimp readily, and come up to the surface to eat as well. You can tell the females apart from the males by the females' fatter bellies, assuming they're fed well. Several of my WCMM's once got what looked like lymphocystis, though it seems to have gone away on its own.

Siamese Algae Eater (Crossocheilus siamensis)

The siamese algae eater (SAE) is a great algae eater to have around in a mid-sized to large aquarium (they can get up to 6''). I got 2 of them off Aquabid at around 2'' to help control the brown brush algae in my 20 gallon. They are one of the few, if not the only fish, to eat this type of algae. Soon after introducing the SAE's, all the bba was gone from the wood, plants, and rocks. Fed on zucchini, they grew quickly, though one is noticeably bigger than the other and chases the other one around whenever they're together. They also eat flake and frozen foods like the rest of the fish, though I've read that this may detract from their appetite for algae, especially as they get older. Still, they're supposed to be more diligent algae eaters than others, like the CAE and flying fox. They are also reported as good jumpers, so keep your tanks covered.

Zebra Danio (Danio rerio)

The zebra danio is an active fish that prefers to be in groups of 6 or more in a ratio of 1 male to every 2 females. It stays small at around 2'', but requires at least a 20 gallon long tank because it's such an active swimmer. This is the least expensive fish I bought, costing me less than a dollar each. Many people use zebra danios to cycle a new tank because of this, although I prefer doing a fishless cycle or getting mature media from a fellow hobbyist. Not a fussy eater at all, the zebra danio will accept most small foods. You can get fry from them by putting marbles into a bare bottom tank. The eggs will drop between the marbles out of the adults' reach. The adults can then be removed before the eggs hatch.

Cherry Barb (Puntius titteya)

Female

Male

The cherry barb stays small at around 1.5'' and is suitable for those who only have small tanks. Some say they do well in a trio of one male and two females, as they don't really shoal that much. I don't know if this is true, but I've had 2 males and 4 females so the females aren't always being chased by the same male. However, the 1m/2f ratio is a good guide to go by.

The cherry barb can be a fussy eater and somewhat shy in my experience, but maybe it was because I didn't have any live plants, which I think the cherries would appreciate. They aren't as active as tiger or rosy barbs, but are also more peaceful and less likely to nip at other fish.

Rosy Barb (Puntius conchonius)

Male in the front, female in the back

The rosy barb is an active fish that prefers to be in groups of 6 or more. They can get to 5'', although mine only got to about 3''. They are great eaters and will eat mostly any fish food you put in the tank. Although they eat their fry, I found I could get fry and raise them by putting up a divider. The fry swim through the little holes to the safe side, where I feed them frozen baby brine shrimp. I managed to get quite a few fry to sellable size using this method. I'm not sure if pH plays a part in determining the male to female ratio of the offspring (like it does with some fish), but I got a lot of females and only a few males.