Use 1 capful (5 mL) for every 80 L (20 gallons*). In some situations the cloudiness may increase slightly after adding Clarity™, however this is normal and is a sign that Clarity™ is actively working. Rapid clarification will follow. In the case of chemical or particulate clouding clean filter filter floss or cartridge after tanks clears. (Note: The 2 & 4 L container’s cap is 10 mL)