the "smell" is starting to get annoying

[Delphinus]

I seem to remember reading about people using carbon filters on the air vent hole of the collection cup used by beckett skimmers. I'm not sure if you could do something similar with a needlewheel based skimmer, although on the flip side usually you put these in the sand or the sump or other enclosed area so you'd think they would not be contributing to "that smell" too much.