the water from you FW tank? I've read where some people don't and i don't understand why not. If you have sanitized your system what is there to be afraid of??
Of course we use it from our tank. Have been for over 110,000 mi on this Bus and over 75,000 mi on the 2008 Bus. Some people don't use the bathrooms or showers in their rigs either ???? Go figure.