Is there any kind of media you can use for this that won't get all gummed up over time? That seems like a pain having to ditch and reseed the media twice a year =/ Also what are you using for a pump to push such a small volume? This sounds like a neat project, I just would prefer to learn from other folks experience rather than keep buying up the wrong things over and over again haha
Take this with a grain of salt :
I dont think it would matter what media is used. Mayne more mech would allow for a longer "clean" period and who knows how ling it actually would take to gum up im just speculating and go off others experience.