The permagreen CAN NOT and WILL NOT work with how it is instructed to use in the manual, you can not use with 7' on center rows. The machine must be used with circular application pattern only. With the 10 o'clock and 4 o'clock spread pattern there is now way mathematically you can get a uniform spread pattern going in rows with 7' centers. The correct way to do a pan calibration test is to use 3" aluminum pans and pour contents from each pan into a 1/2" diamiter tube 4" tall. Add all numbers together then divide to find percentage in each pan........If done this way you will see the glaring issue with the machine!!!!!!!!!!!