[JustOneMore20]

Golden Chinese Algae eater? Stay away from those. They get around 8" long full grown and get more aggressive with age. They aren't good candidates for a community tank, much less a smaller one.

Stick with various Cories. Those are community friendly and can live in a 20g. You should get a group of the same type. 6 would be good for your tank.

For smaller tanks, there aren't too many options. Plus, shrimp would most likely get eaten, so they're out. Otos don't hang out on the bottom all the time. They are algae eaters, so they stay on the glass. Cories will scurry around the bottom and if you are looking for something to hang out there, Cories are great. Most loaches get too large, except for Kuhlis and Dwarf Chain Loaches. Kuhlis hide alot though, so you may not see them much. Dwarf Chain Loaches are pretty rare at LFS and expensive when you can find them.