How often do you drain your air compressor?

J-c-c said
I used to when buying brand new compressors/tanks, would open it at the top, drop in some solvent slosh it around, drain it out and after a decent amount of dry time follow that with some (pint?) quality paint, and slosh that around and quickly drain, the idea is to give some protection to the bare metal inside where water would constantly collect daily.
I now have an aftercooler right after the compressor, that has a fan on the same circuit that runs with the compressor. Aftercooler next feeds a water trap with an auto drain. Being in Florida I am still amazed how much water still gets into the 80 gal tank,

I live in Iowa and we have a lot of humidity in the summer. Back when at the Buick dealer, all the tools were not powered and every hoist was a air powered, in ground lift. It took a lot if air. We had a 10 horse 250 gallon. We finally installed an auto air purge and there was still gallons of water that was drained out every day.