I was able to dry out the Koi Filter a bit yesterday while fishing. The Media Foams you don't clean spotless unless you have a biological problem where you Sanitize them. I do Sanitize all the hard plastic stuff like the pump housing, tank, chiller, all lines, the Filter housing, etc. before storing assembled once full dried. Allowing the Environmental Media to air dry leaves dormant enzymes that help with a quick startup when the time comes for charging the tank up again. I Sanitize using Star-San, same thing I use in Wine making. I kills the stuff we can't see after washing out what we can see.