I have a polyethylene cylinder exactly double the diameter and length of a toilet paper cardboard tube, attached inside the cylinder 3" from the topside of the cylinder I have a tightly secured round vented 10 Micron plastic carbon filter disc encompassing the entire inside diameter which only allows air to flow threw the filter , my question is "If I connect a small electric fan to push air UP threw the Cartridge filter will I get the same flow ratio opposed to drawing air DOWN threw the carbon disc filter? is one direction somehow more efficient? Should I use an Impeller or Propeller fan? I hope I have been clear in my description? I'm not even sure if I have a physics question here?? Thanks for your help, I do appreciate it.