[trenac]

A great active, colorful, hardie small fish is the male Endler. The only drawback is that they can be hard to find locally.

I would also suggest for a clean up crew a couple of Dwarf Corys and a couple of Amanos for algae cleanup.

 

[trenac]

I myself was going to suggest White Clouds but decided against it, because IMO they need more room to swim about in then a 5G tank can offer because they are so very active and unless kept in schools can be aggressive. These fish can be kept in Cooler temps but also do fine in a 76-78 degree tank.

The above statement is from my experience with White Clouds, not to undermine what Jan contributed.

 

[trenac]

In a 5G tank I would not put Danios, unless keep in groups of 5-6 they will lash out at other fish. If you are going with the Betta I would make that my only fish, you can still add some Dwarf Corys fr clean-up. Another fish that you could try is a Dwarf Platy, Male Guppys would also work. I agree to stay away from Neons or any schooling fish for a 5G tank.

 

[trenac]

Just to let you know that Glass shrimp are not good for algae control, they are mostly a scavenger and would more than likely become a snack for any fish that can fit them into their mouths.