Quote Originally Posted by IRescue452
Charcoal is only active for 7 days, it does not help the tank cycle.
Actually, chemipure does remove ammonia and nitrogenous waste. It's reported to last up to 6 months though most of the reef-keepers I know dispose of it after 3-4. (Rinse it when you do your water changes to get any debris off.)

I don't know if it'd be more advantageous to introduce it into a cycling tank or an established tank.