About 3 years ago I got my chem. license to spry the local school fields (about 30 acres in all). I bought a Schiban pull boom spray rig with a 3.5 motor and 60 gal. tank it has 18ft. booms. At first this was all I was going to spay but I am seeing the profits of chem applications and residents are asking me to spay their property as well. I am considering buying a skid sprayer but I am having a hard time trying to figure out my mix rates if I use this set up. The formula for a boom sprayer is so much simpler to figure out. I also have herd of multiple products in the same spay application ( herbicide, potash, and fert) is this possible. I know you cant do this with a boom because of the gal. per acre applied. Am I thinking to hard or is it easy to figure out once you have the system?