Don't forget your licensing will have to change. You will have to get a custom applicators license, not just private applicator.

Also, if MI allows you to license your water truck as a farm truck, that will have to change as well. Once you start in as a custom applicator, you have to license them commercially.

Finally, insurance. Makes sure you are covered for misapplication, drift, regular liability, and excess liability if you were to do something really wrong.

Also, if you use tank cleaner, make sure you rinse it out really well. It is one very efficient corn killer.

Good luck.