Tetra AQUA Safe removes chlorine to make tap water safe for fish in your aquarium. Use it monthly to condition water and protect fish works instantly. The powerful slime reduces stress. Treat water when setting up a new aquarium and with monthly partial water changes or evaporation replacement. Add 2 teaspoons (10 mL) for every 10 gallons (38 Liters) of aquarium water. Make sure that replacement water is the same temperature as water in aquarium. Use Tetra AQUA Safe every month as part of a 3-step program for essential water care: Tetra Cleaning Bacteria cleans the aquarium, removing ammonia and sludge; Tetra AQUA Safe conditions water to make tap water safe for fish; and Tetra Easy Balance balances water quality to reduce phosphates, add vitamins and regulate pH levels.