I have a 3-4 inch marble goby in a 20 long. I believe base print is 30"x12". Now after this he's going into a standard 120g. I had him in there but he seemed lost, like there was to much space. My concern is him eating. He only takes live which is fine by me. I quarantine the feeders and fatten them up before feeding. But will he be able to catch them? I have plenty of drift wood. He can get high enough to grab them on the drift wood. I just want to make sure he gets enough. Tank mates would be an odoe pike, hoplias curupira that I ordered. Possibly an ornate and mala. So what do you guys think? Put him in the 120 or leave him in the 20 and try to get him to grow more?