I've got a Marineland System 6 tank, moderately planted with some neon tetras and a corydora in it. I decided to pull the bio wheel & raise the water level equal to the filter exit to reduce agitation for the water surface to help boost C02 in the tank, even if it is just moderate. I would like to get away from using the factory replacement media which contains carbon. What would you recommend using? Something I could rinse off in old tank water & re-use would be a plus but I don't mind a replacement media if it isn't too expensive.