I have three of them. My suggestion would be to leave them alone as much as possible. They go through phases. Some days they will be huge and puffy, and on others they will be tiny. I think that the key is to leave them alone when they are small. I have never fed them directly, I just let them feed naturally. I have them at the bottom of my tanks, so don't think that moving them closer to the lights will make them any bigger. That's my opinion, good luck.