New to the system, I'm still trying to figure  which way all the valves go in order to perform certain tasks. I think AC  a link on here somewhere showing various positions, as far as spraying, mixing, on loading bleach to bulk tank, etc. 

I did my first roof today, my own office roof, did half to use as an advertisement, WOW, what a difference. Not going public til I go thru modules. Still lots to learn. 
I only Mixed up 25 gallon. I knew when I was going to run the BW thru at days end and  that I was going to waste product. And I did. I had all kinds of stuff mixed together in that first tank. I just triggered the wand open and sprayed all out in the  rocks. So yes I wasted some product jacking with valves,  but that's okay As  It's on my own property.