What I want to do or know
For the purpose of this question assume the activated carbon is a typical fish tank product like used in the plant air remediation build, with particle size of (guessing?) 2mm-5mm, and the carbon is also most likely very moist but not submerged.
I believe the measured output of the pump is roughly 1L/m spread over a diffuser, so net air flow is not high.
The air pump on the plant based air remediation build has a tiny fiberous (paper?) filter through which we pump air that has been through the activated carbon. One concern in blowing air either way is whether or not we would be adding significant contaminants to the indoor environment because of the activated carbon or growth media. A follow on question is: does the paper filter have any effect on the particle size (if any) that we're concerned about?