17-4-17 is a special formulation for the ornamental market, including not only flowers in a greenhouse environment, but mums and other plants started outdoors.  As with all of the ISP plant foods, the trace mineral package has been put together with the needs of these plants in mind.  Normal use early is to inject at a 600 ppm level, then, once the plant has become established, reduce to approximately 400 ppm levels.  It is designed to be injected through spot specific irrigation methods.