like in the first post tangs love spirilina based stuff (green) i feed mine seeweed, and spirilina flake, and he eats the other marine food that the other fish like as well, but i make sure he gets his own special treat. He also eats the alge from the outlet tube of my protieb skimmer. I scrape it off and he eats it right up! Tangs can be suseptable to marine ich, and mine has had it twice. Once when i added another fish, and he got stressed out, and one time when i had to move my tank due to moving households. Stress causes ich, so don't let any other fish stress him. And he will love to swimm, so make sure that the tank is not filled with rock so he can swim from one side to the other. Mine will be going in a 120g once i'm sure my cycle is complete, and i'm sure he will be much happier than he is in the 33g. He is about 3 inches, and he came with the tank, but i would never have bought him for a tank that small.