I went to PetSmart yesterday & discovered that the otocelifer catfish were on sale for $1! (1/2 price.) I ADORE these guys. I bought 12 (I had 2 already) for my girls' 29 gallon. The fish are TINY! Neon tetra size. They are amazing algea eaters. I bought 5 for a 2.5 gal w/ a bad green algae problem. The little guys hd the tank sparkling within 3 days. The problem is that these are extremely delicate fish. They are wild-caught in rivers, and prefer cool, soft water with a good current. I lost 3 fish in 4 days. That being said, the 2 remaining are awesome- I looked them up on the web, and they can live 6-9 years in "classic" tropical tank temps if they're healthy. I expected to find a few dead otos this morning, but all are doing well. I did take almost 12 hours to adjust thier bag water to the temp & Ph of the tank; I think this helped. I'm sure I'll lose a few, but that's why I bought so many.
They are chowing down on the algae in the tank & the driftwood. The bettas aren't intimidated by them, but they enjoy a good chase! No betta can outswim the otos, so the otos don't take them very seriously!