Key Features 100ml Spray bottle Helps improve biological filtration Removes impurities in the water Is 100% natural and safe Can be used in all aquariums The Oase biOrb Water Optimiser is a simple and quick way to improve the quality inside a biOrb or any other aquarium. The Water Optimiser improves the biological filtration, removes impurities from the water and benefits the overall well being of your fish. Add a few squirts to your aquarium every week to help keep your tank water crystal clear and healthy. The spray is suitable for all aquariums and is 100% natural and safe. You cannot overdose your aquarium with this fluid. Specifications 100ml bottle 2 Pumps will treat 15 Litres Shake bottle for 10 seconds before use Note-The water will go cloudy as treatment is added but will return to normal within a few hours Suitable for Marine Tanks