Trip cancelled – leave black tank as-is for a month? October 17, 2025 at 5:00 pm #54463 Tory JonKeymaster Joined: Nov 2019 Posts: 611 Likes: 858 LikeUp0:: You have nothing to worry about, unless you live far North and it potentially freezes in the next month, but thats more of an issue with water in your lines.