"The problem with gearheads is they are always looking for something just a bit better even if it doesn't result in any significant improvements in results. The striving for that ultimate bit of gear becomes as or even more important than the art of photography. Because of that they are more aware of which products perform the best in any given area."
Stole this from a photo-gear forum and realized how this can apply to growers as well.
Just substitute growers for gearhead, growing for photography and fertilizer/media/lights for gear.