Protein skimmers can churn up some nasty, foul smelling stuff. Because of this, it’s commonplace for aquarium rooms and tank stands to be very unpleasant on the senses. To knock down on the smell, you could clean your skimmer cup every couple of days, but who wants all that effort added to an already extensive maintenance routine? Instead of adding more tasks to you day, try laying a bag of activated carbon on top of the protein skimmer’s lid. The carbon will remove the smell pretty effectively, and it’s cheap and easy to replace once the smell starts to rear its ugly head.