do you keep water in holding tank between trips?

The problem even leaving the tank drained between uses is that the tank has virtually no ventilation other than the vent & that doesn't allow enough air movement to allow the tank to dry itself out. The result in hot weather is mold. Ask me how I know.... I now fill it after each outing & add 5 or 6oz's of bleach, run that thru all the water lines. Prior to the next outting, I will fill & rinse all of it at least three times before the fill to go.