At the bottom of your air compressor tank there is a screw and every month loosen the screw and let that water drain out of the tank.Thanks for the link Sergio.
A fact or question about using an air compressor instead of the compressed air.
Moisture is expelled from within the hose and tank which could harbor pathogens
so wise choice to use the can of compressed air. It irks me when I use my air compressor
to blow off saw dust from fine wood working and it sprays out rust water.
I still do it, but I'm not sealing it up within a living tree either.