Originally Posted by bettaboo
apperantly the filter refills already have the carbon built in them
Yeah but Chemi-Pure works a lot better than just carbon because it filters other things like Ammonia, Copper, etc. I use the Elite version in my nano reef and I swear by it. Another option would be the Aquaclear 10 as someone else suggested but that one has more flow than the Tetra.
I will take a video of the flow with my digital camera and post it so you can check it out and see if the flow is to your satisfaction.