Good video, thanks for the ideas. We currently use one plastic, 46-gallon RV tank for fresh water hauling and another for grey/black water transfers while long-term boondocking, but they take up a fair amount of space (14"X19"X37" I believe.) I think we might replace the fresh water transfer tank with one of the pillow tanks you use, that's really slick.
Also, definitely going to get a portable digital water meter like you use. I have been wanting to know just how much we are putting in our tank, as we fill it different amounts for different reasons (just enough water to travel from camp to camp with, enough for a few days, etcetera.) That meter is just the thing!
One thing that might make your life easier (it has mine!) is hose quick connects between the hose and tank. They eliminate the need to thread/unthread (rotate) hoses and fittings, especially useful on the male hose end that doesn't have the swivel collar built in. Super quick, no twisted hoses.
These are the ones we have
https://www.amazon.com/Melnor-Quick-Connect-4-Piece-Garden/dp/B00004SDUW/ref=sr_1_8?s=lawn-garden&ie=UTF8&qid=1518134493&sr=1-8&keywords=hose+quick+connects , not the best quality, but they are cheap.
There are better ones out there made of brass that I plan to upgrade to once I figure out a reason why these just aren't good enough.
Thanks again for the video!