Chemicals are an essential ingredient to successful aquaculture and have been using in various forms for centuries. There is however, a huge concern about using more and more chemicals in aquaculture with its rapid expansion and intensification. Health management and disease treatment is one of the major areas where a lot of chemicals and drugs are used. This book provides a comprehensive review and field data on the use of aqua chemicals, their categories, application and impacts especially on aquatic animal health. Currently, many pharmaceutical companies are either manufacturing or importing new products to expand their business in aquaculture sector. This study also compares between traditional and new compounds. It may be of great use to the students, researchers, extension workers and people interested in aquaculture.