[Wally Arntzen]

Thanks for the private message Mike.
All of my tanks have a shraeder valve on the bottom and my mechanic friend has a one quart tank that connects to an air line. He fills the quart canistor and blows the alcohol into the tanks. I leave the alcohol in the tanks through the winter and drain them in the spring.
I generally drain the air out of all my tanks 2 to 3 times a year. I generally put 30,000 plus miles on my coach annually so draining the tanks depends on the usage of the vehicle.