For information on maintaining and rearing clownfish, this book is unbeatable. Every aspect of culturing and rearing marine fish, from hobbyist's tanks to large commercial operations, is described in detail. His opinions are supported by actual data, either from the records of his years in aquaculture or from the scientific literature. Thus, when he writes about the importance of a given parameter, it is more than just a casual observation or repetition of lore. The focus of the book is the production of healthy baby fish, which requires healthy adults, eggs, and larvae. In a systmatic way, Hoff describes the effects of filtration, light, water conditions and food on all life stages, providing an integrated view of the process. Although this is not the "only book you will ever need", it is a valuable addition to the collection of the experienced aquarist, and would help to eliminate much mystery for the beginner. The prose is not helped by the grammatical and typographical errors, but is generally straightforward and clear. Info from amazon