Tap water control from TAP Aquatics is suitable for cold water, tropical and marine aquariums. This product makes tap water safe by removing chlorine and other harmful toxins. Treats 565 Litres. INSTRUCTIONS: Add 1ml per 4.5 Litres (1 Gallon) of aquarium water using the accurate measuring chamber provided. Add to all new aquarium water, including when topping up and for partial water changes. Tap Water control works in minutes converting harmful tap water into safe aquarium