Oh no, tannins!

Buckets are hard to come by?? Rofl (:
 
any hardware store worth anything should have at least the ubiquitous white 5gal painters bucket. Thats what I have.... cost me $2 and works great
 
Would be easier just to add fresh carbon to your filter. If you have a filter cartridge you can always put some carbon in a piece of pantyhose, or a media bag and put it in your filter or near the outflow of your filter. Just remember to change it as others have said, it gets "full" after a while.
 
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