I'll make this short and sweet. Buy this book and read it; you'll be inspired to investigate the world of hydroponics. The author's enthusiasm comes across and makes one want to start experimenting before the book is finished. The full color pictures tell a story all their own. You can see what it's all about. I never considered that there were so many types of hydroponic methods. Dr. Sutherland extensively covers various plants and their needs. He recommends certain vegetables as his favorites and why. The big three mediums seem to be: perlite, vermiculite and "growool". If there was a negative to the book it would only be that the author is in Australia, so most of the appendix is directed toward Australian and New Zealand suppliers. Thanks to the internet I don't think that is such a big deal. If you haven't guessed it by now, I enjoyed this book.