westend wrote:
There was a thread, recently, by a gal in FL that left a tank valve open and left her new trailer. While she was gone, the campground sewer system became blocked and flooded her trailer with sewage. IIRC, the trailer was a total loss.
X2. After reading that post, I won't even leave the gray tank valve open.
To the OP; the idea of dumping your black tank involves flushing out with lots of water. So even if you used the black for 1 day and there is very little in it, the best thing to do is add a LOT of water so you get a good "woosh" when you drain the black tank.