I am not sure of whether it is true or false on the carbon, I think carbon would be useful once per month or so to remove yellowing agents, if nothing else. It is true you do not run a skimmer. I have heard good things about this system although I am skeptical of the mud an analysis of the mud can be read here
. I know at least one of our members uses the Eco-system (CMK II), you might try sending a pm.