I agree that carbon life depends upon the stuff in your water. I used only in my salt tank and only for about a week. I did then use the filter with just the pads to help remove the "big" stuff and to provide additional area for the bacteria to grow on.
A water polisher is a common term for a filter that is designed to filter out small stuff. Very early models were actually like a porous stone with an air tube in the center and they were powered by an air stone. Today they are paper element filters (similiar to but different from you car's air filter) used in canister filters. As they plug up the remove smaller and smaller particles.