Size 118ml Aqua Essential water conditioner is a highly concentrated all-in-one water conditioner that instantly makes tap water safe for fish by removing chlorine, chloramine and detoxifies heavy metals commonly found in tap water. Aqua Essential water conditioner instantly removes toxic ammonia, nitrate and nitrite levels in freshwater, saltwater and planted aquariums. Toxic ammonia continually released by fish through their gills, urine and solid waste. Uneaten food and decaying organic matter also add ammonia. Small amounts of ammonia stress fish; large amounts of ammonia will kill fish. This unique formula binds with ammonia, nitrite, and nitrate rendering them non-toxic and allowing the biofilter to more efficiently remove them. Instructions: Using dosing cap on bottle, add 5 ml. per 50 gallons of aquarium water to treat tap water. Add 5 ml. per 10 gallons of aquarium water to remove ammonia, nitrite, and nitrate. If you dose within that 24 hour period there is no danger to the animals/plants in your aquarium. A follow-up water change is always beneficial to an aquatic system.