Gosh in the 21st century cell phones that reach about everywhere and Dad didn't check to see what was in the tank last ??

Welllllllllllllll,,, lest we can all visualize how long it takes to "flush" a tank before switching chemicals in a sprayer...........    Bout, oh 4-5 acres it looks like?

Cell phone aside,,,seems like a "low tech" fix would be maybe pulling off the chem container labels,, sitting them on the tank, placing a rock on top to keep the labels from blowing away would have been appropriate???

Kinda expensive way to learn about importance communication.

just my 2 cents....