Since I am a newbie I asked friends with rV's about winterizing. One told me to open my valve to let things dry out in the winter( assuming poo and TP that want't washed out) so it comes out with an easy rinse in spring time? My trailer has a black tank flush, so I did a really long wash last weekend during my last camping trip and kept my valve closed for winter. There will be a little bit of antifreeze in my tanks from the process.
TT: 2015 Jayco Jayflight 26BH Elite
TV: 2014 Ram 1500 Sport, 5.7 HEMI 3.21, Firestone 1000# air suspension. WD hitch w/800# bars
SOLD: 2012 Jayco J-series 1007