About the residue on the tank sides: Was the tank washed prior to experiments? It may be that the first test with the 3" hose allowed the water tension on the sides of the tank to be relieved by the flow of particulate across the sides (scrubbing pink micro-ish). The following tests, especially the rinse cycle would have relieved even more water tension to the plastic sides.
As long as your willing to run more tests and in the interest of waste tank science, maybe using additives like the Geo method, enzymes, and RV specific tank cleaners could be a series of tests.
I didn't mention it in the video, but I actually cleaned the tank with Windex before each run (and after the last!). I had run some test runs before we started filming, and I wanted it to be clean. But you're not the first to suggest surface tension on the sides, and I'm wondering if I did something differently. Next time, I will follow a written procedure to reduce any variables I may have missed.
I think my next run(s) will be with tank additives. Many folks seem to be interested in that. My trouble is, I'd have to leave them in the tank for a while. I'm not sure how long is "long enough", and I've got to keep the tank somewhere while it "steeps". SWMBO says a tank of simulated waste in the yard, percolating for days, is a no-go. May have to put it on a cart and keep it in the shed...
Thanks!
