Carbon is not required in any tank if you keep it up properly. Carbon removes colors and odors, but is only a bandage. It will eventually stop doing so. Keeping up on water changes, once every 4-7 days in planted tanks, will result in optimal conditions for plant growth and overall tank health. Cabon isn't "bad," but it's only a tool to be used when needed, such as removing medications after treatment.
If you have a "noticeable odor," you may have some water quality problems. No tank should have a bad odor, only that "water" odor, the smell you smell when you are at the lake or near a creek, river, other body of water, and even that should be minimal.