Bigger the tank,bigger and faster they grow, in my humble opinion. Feed it constantly. I would try to use some type of pellets hidden inside other meaty foods if you can. They have ALOT of protein in them. I have used Hikari Massivore Pellets with EXCELLENT results. I feed mine lots of different prey items as well. Anything from whole gut loaded fish to frogs,and everything you can imagine that's meaty in between. Also, lots of water changes. I do mine twice a week. I don't change as much,but I do so more frequently. I think it's better like that in my humble opinion. Less of a drastic change in water parameters that way.