What is the procedure for replacing the innards of the tank vapor canister and are they directional? Also, is there a source for the activated charcoal for refilling? Maybe a thread somewhere on how to refresh the canister. Thanks for info in advance.

Pet store, fish section

mmm... sounds good... barbequed fish!

I'll have one Mahi. I'm not hungry enough for Mahi Mahi.

Look for pelletized charcoal at Amazon. Not the 'chunk' style. Far cheaper and you'll get enough for a couple of canisters.

Amazon is where I got mine