You could put it in an internal filter and use it basically as a reaction chamber. I shouldn't image it will hold that much carbon, and what impact it would have on your water chemistry would largely depend on the size of your tank / water volume too.
A word of warning though about Carbon. I used to run active charcoal chips / carbon in my old Jewel Rio 180 sump, but stopped using it as it added to the phosphates and my coralline was struggling. If you do run charcoal, run phosban or grow cheato in your tank/sump.
There are benefits to running carbon as it does absorb impurities and toxins from the water and it always seemed to make my water clearer too but, it will leech phosphates into the water, even the ones that claim they don't.
cheers,
AK
