you are referring to 'foliar feeding', you will still have to water at the roots - it is virtually impossible to over-fertilize your plants that way, if done correctly - first, mix your nutes 1/2 strength, and spray the UNDERSIDE of the leaves, (that is where it intakes the nutes, not on the topside) - don't spray the topsides, as the drops magnify the light, possibly causing burns - try to spray them early in their daylight hours, when the lights have just come on - I did all my grows with ONLY foliar feeding, giving them a shot about twice a week, for many years, with excellent results - the ONLY reason I don't presently do it, is because the over-spray makes a real mess of my Mylar - foliar feeding also gives you a quicker 'result window' when trying to diagnose nutrient deficiencies, usually showing a result within 2-3 days - be sure to stop all nutes 2-3 weeks before harvest, and spray with clear water, to rinse off any residue - :smokin: