Carbon is a useful tool for removing chemicals from a tank. It can be important after medicating a tank and when you're ready to remove the medicine so it doesn't effect the other fish anymore. The dispute with carbon is over how long it is truly active in your filtration. Once the carbon is saturated it can actually start releasing chemicals back into the environment and cause it's own problems. Depending on your setup this can happen in as little as one week. So, i like to keep some on hand for emergencies, but as long as everything is running smoothly it is usually not needed and i prefer not to use it. Jesse _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member