Thanks for this post! In a wild-eyed fit, I just got 6 otos, a cobalt stiphodon goby, and a Florida flagfish for a 16g hair algae-infested tank (it was that, or smash the thing with a hammer--I was sick of it). I will be curious to see what works for you with the otos. So far mine have survived almost a week, but I've been warned they could still drop at any time. I wonder if it isn't internal parasites that do them in?