Grey open all the time (until our last full day, then I close it)
Black closed ALL the time. You don't want paper and other solids getting caught in the tank. Gravity takes them out when you pull the valve and there is liquid to go with it.
Empty black first, then grey.
2016 Grey Wolf 26DBH following a 2014 RAM 1500 Outdoorsman
Life is good...Live it!
(2014) Nights Camped - 16 in 6 trips (2015) Nights Camped - 20 in 6 trips
(2016) Nights Camped - 21 in 7 trips