When camping in full hookups I always keep my grey tank closed until full. When dumping the grey tank it smells worst than the black? Would it be better to keep the tank open or closed?
Ditto Dennis' method. We leave the gray open and always the black closed. When we get ready to dump the black, every week or so, we close the gray, both shower and we run at least one load through the washer. Then dump the black, when empty, we let some gray in the black 2-3 times and dump again leaving some gray to finally run through the hose to "clean" it all out. And yes the gray can stink as much as the black!