i stopped subbing out fert programs, and started doing my own this year. i understand that while keeping records, the amount of product used should not include any fert thats mixed in. ok, so i want to see if im doing this properly. the bag says it contains .13% of the chemical, and the remaining is "inert materials". so, if im applying 4 lbs per thousand sq. ft, and the property is 2500 sq. feet, then 10 lbs of total material was used, and 13% of that was the chemical used, this comes out to 1.30 lbs of herbicide used. is this the right way to do this?