Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: A "Practical" (??) guide

The title of this book indicates that it has some some of how-to information in it. But that is not the case at all. It has lots of information on the nutrient solution, but it not really helpfull if you are buying yours premixed.The book totally lacks conclusions that is needed for decisions when setting up you own system. In other words not a how-to book, so only two stars since I'm so disappointed