The ink below may be of some help.

Here is a link that might be useful: calibrating a spreader

If you are always getting fungus you might have a problem with too much watering or bad drainage. I got hit once last year behind the garage that was a low spot and only got sun a few hours a day. I dug it up, added dirt/sand/peat moss, alfalfa and new sod. I did not get hit with fungus this year. I did spread out corn meal on the fungus problem last year by just tossing it around to cover everything. I don't think you can "over do it".