If you're a beginner, this book will give you a beautifully illustrated step-by-step guide to starting your first aquarium. If you're an intermediate, it will give you a detailed understanding of the wonderfully complex chemical, biochemical, and biological processes going on in your aquarium, and how to turn them to your advantage. It will also encourage you to create "biotope" aquaria, in which the species and the conditions are precisely suited to one another, as they are in nature. If you're an advanced fishkeeper, it will challenge you to throw away most of your expensive hi-tech appliances and work with nature! And, into the bargain, it will challenge you to become a conservation-minded aquarist. Quite simply the best aquarium book I've bought in twenty years. I only wish Tullock had gone all the way, and described mangrove and "Miracle Mud" systems, in which all filtration is entirely natural.