Aquarium Care Sheet : This article aims to provide an exhaustive analysis of TDS management in freshwater aquaria. It moves beyond the simplistic view of TDS as a mere number to be adjusted, exploring the nuanced relationships between dissolved solids and biological function. Table of Contents Introduction The Evolution of Water Quality Monitoring The "Invisible" Parameter: Defining Total Dissolved Solids The Scope of Hydrochemical Management The Physicochemical Basis of Diss