what about running a mag7 from inside the tank in a closed loop system? And what is a good fairly cheap external pump? said:That should work, you'd just have a big unsightly pump hovering inside your tank...
There are many options on external pumps, I've personally had great luck with Quiet One pumps, although some people haven't had such great luck with 'em...
(Quiet One's are internet or external, like the Mag, but better able to handle being run externally)