regarding molasses.....Passive hydro is no problem--no pumps, filters or small tubing to plug up. The molasses is feeding the beneficials in the medium, which acts like soil in Hempy's case (water, drain). I don't think you can over do cal, mag or iron because the amount is so small. (Last sentence says to treat your "water" as you normally do--calmag, ph etc. There is sulfur also to help terpine development.