I've tried weighing them down onto the gravel twice, and let one float on the surface, but the otos just won't touch it. I don't think they know its food they can eat. Is there any way I can teach them to eat it? I don't think they are getting enough food as there isn't enough algae in the tank, and I don't think I want to try out algae pellets just yet. I heard otos actually love zuchini, so I'd like to let mine eat some.