Has anyone 'reverse engineered' the fertilizer solution in those applicator sprayers that attach to a hose? Seems like a good idea, especially for folliar feeding, but the price per bottle of solution, not so much. Yeah, they claim the bottles aren't reuseable, but I have.

Now before I go out an purchase a couple of test kits and try to remember my college chemistry WRT moles(and I don't mean the burrowing kind....)grams percent and whatnot, has anybody done this?

Cheers