This is one of ten eBooks on the commercial production of ornamental fish. It is based predominantly on the author's 30 years of experience, mostly on his own farms. While a few of the eBooks are purely commercial, others, particularly those on breeding, will also be helpful to hobbyists, understandable even by beginners. The following description is provided as a guide. This section gives a detailed background to some important aspects of fish breeding and commercial production. These include: a look at water and how it supports fish life in the natural environment, basic water chemistry from a fish breeding and farming perspective, an overview of production and general breeding methods for different groups (families) of fish, commercial suitability of major families, identifying the sexes, advice on obtaining breeders, and how to quarantine new breeders. Potentially useful to both hobbyist breeders and commercial producers.