Specialized book on keeping saltwater fish and water quality management. - Title: Coral Fish No. 16 - Contents: Book about keeping and enjoying saltwater fish - Special Feature: The Core of Water Purification - Theme: Knowledge to prevent fish from dying - Published: 2020 Thank you for viewing. Many saltwater-related books are available. They are all old, but in good condition considering their age. ● Other Notes: This item is available for immediate purchase. Please consider this a used item and understand its condition before purchasing.