So I got a IM penn, mostly due to the coral it had in the tank, ended up being cheaper to just by the whole setup lol. That being said, it currently has a Orbit marine on it and I dont feel like the coral is likeing it all too much. I was considering selling it and getting a AI prime 16HD or a AI Hydra 32 HD to use the tank as a frag tank (a bit early I know but but it was too good a deal to pass, if nothing else, I can just resell it haha). Any suggestions? Would the AI prime 16HS be enough for a long 20gal? Maybe 2 of them? Or would it be better to just get a hydra 32?