OK, another trip and another helpful hint proved to work. When you talk to RV owners it is always interesting to hear all of their “home remedies” and quick fix solutions and, of course, we have to try a few of them. I recently read that a great way to clean your black water holding tank is by filling with 10-15 gallons of water and ½ box of Calgon Bath Spa (for us old timers, we recall the “Calgon, take me away” commercials). We did this right before we left for a 4 hour drive and then emptied the tank at the campsite. It’s amazing how well it works and the RV had a clean fresh smell. Looks like it worked so I wanted to share this idea with others.