i want to add some fertilizer in my air seeder, european ACCORD (mecanical ground driven). i want to add a second meter that will put seeds in the same air delivery hoses
this meter will be driven by a small 12v motor. i want to adjust the rotation speed (=the rate) to the ground speed with my gs2600. the builder of the fertilizer meter can only provide a box in the cab on wich  you adjust the motor speed manualy with a rotary knob.
what do i need to add, jd ref and prices?
thanks