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Chemistry Chemistry

TDS (Total Dissolved Solids)

The total concentration of dissolved minerals, salts, and organics in water - a quick indicator of water purity and hardness.

Unit: ppm Code: TDS

📊 Ideal Ranges

Freshwater
100-350 ppm

📖 Overview

TDS is a rough but useful proxy for overall water composition. Distilled water has 0-1 ppm. RO/DI water 0-4 ppm. Tap water varies 50-500 ppm. Neocaridina shrimp thrive at 150-250 ppm; Caridina bee shrimp require 100-150 ppm. Monitoring TDS during water changes catches problems (RO membrane failing, tap water contamination) before they harm livestock.

🧪 Testing Methods

Digital TDS meter (essential for RO systems and shrimp keepers). Calibrated conductivity meter (more precise).