Plants don't hold nutrients in them at all, when nutrients go into the roots they get turned into other things prior to going up the stem the root system does it by the time the nutrients hits green it has already been turned into something else. Flushing is "broscience". Have you ever gotten drops of fertilizer water on the leaf of your plants...that should be more then what you need to understand. Plants literally can't survive in fertilizer you already have the proof if you have grown 3 or more Plants xD ( add me for pictures of the best homemade stealth grow ever)