How are you swapping between the two tanks?
-Unplug one, plug in the other..
-Tee both into one line, manual valves (how Skittles is)
-Electric solenoid to switch between the two lines.
Right now I’m just manually swapping the hose. But I have every intention of doing ball valve set up. Are you just using 90* twist ball valves for your setup? There is usually a pretty big warning when I’m running out though, so I just pull over and swap them.
Having a manual valve setup would be way better.