I have one of these guys! He's my favorite fish, sooo cute! I couldn't find a ton of information about them online, but mine has been thriving on frozen blood worms. I feed him with an eyedropper and it's kind of a pain because he's picky and likes his food moving, but my sister has one in her tank and it'll eat anything, so I guess it varies from fish to fish. I also give him those tiny little snails you see in pet store tanks, they'll give 'em away for free. I have in a 2 1/2 gallon tank with a Red Sea filter, alone, and he's been doing wonderfully since I bought him in September. You could probably keep a few in a ten gallon, they can be social fish as long as there aren't too many males in too small a space. I reccomend these guys, they're a fun fish with a lot of personality!