content: This book contains exactly one chapter on hydroponics and it's not a very good chapter. As a general book on growing, it's not bad, but anything that purports itself as being a "grow bible" should include extensive information on evaluating hydroponics systems and mediums and how to use and maintain them throughout a grow. This book contains some information on this, but not nearly enough. For whatever reasons, it includes far more information on genetics and breeding, but most growers I know buy clones or seeds. Those pages would have been better devoted to all things hydroponics.Is there a good book focused primarily on indoor hydroponic growing? Not sure I need it now, but it would have been great to have a few months back.