I'm looking to add volume to a 4g pico, so I know I need to drill the tank, but where would I find a small bulkhead? I was thinking of hiding a bucket or rubbermaid behind or under a couch just to "buffer" the water some. sound like a dumb idea? it's either that or a canister filter with just a bunch of filter floss. Just trying to think whats cheaper and/or better for the long run.