I think the FX-5 is a bit of a pain to clean, although everyone else seems to think otherwise. If you want to use cannisters I like the Rena XPs they are so simple to clean. I never used the G6. I would love to know how it works out. Turtles produce a huge bio-load. I like to use wet dry filters, especially if you know how to drill a tank. You can throw a bunch of carbon in there, and the maintenance is so easy! Just a thought.

Good luck!