Add one tablet to each ten gallons (40L) of aquarium water.
NOTE: For aquariums 40 gallons or larger, and for soft water and/or acid water with low alkalinity, dissolve tablets before adding to aquarium. Use Tetra test strips to monitor pH and alkalinity levels. Use half strength for scaleless or sensitive fish. There is no need to raise the water temperature. Remove carbon from filter during use. If ick persists, treat every 24 hours until it clears. Change 25% of the water before adding any new dose, add Tetra Aquasafe to all tap water.