A lot of different ideas. I've had some serious problems with some good old pyramids. I know after my surgery for a doctor running a scope through my colon, the removed 10 inches of colon. No cancer, just screw ups bys the doctor. Anyway it made things more sticky. Finally when Cameo was just about 6 weeks old we went to unique digest it. He also used it overnight to eat down my pyramid. My trade in also had the pyramid. I do leave the black tank valve closed until time to drain, then wash with black tank flush until clear piece of pipe is clean. One critical thing I have learned. Do not let unique or Happy Camper freeze. It seems to kill the ingredients, and pyramid will began again. Maybe some of you do not need anything, but I do. We are all a little different.