Refugium and carbon

[tuck]

Hi

I have a 55ga without a sump and no room for one. I would like to add a HOB refugium where my filter (which only has charcoal in it) is now. I was thinking of incorporating the charcoal into the refugium I just haven't figured out how to yet. What do you think? is it possible? is there already something on the market that will do this? or a DIY project? is it even a good idea?

Suggestions, experience would be great, thanks.