TLC StartSmart Complete Freshwater, 32 oz, can be used both for cycling a new tank and for water clarity. To Instantly Cycle New or Problem Aquariums: Set up the tank normally, de-chlorinate, dose 1 oz StartSmart per 10 gallons. Add fish. Tank will be cycled in 24 hours. To Maintain Clarity, Digest Sludge: Dose 1 oz per 40 gallons. Repeat weekly or at least once a month. To Solve Water Clarity Problems: Dose 1 oz per 20 gallons, weekly, until clarity problem is solved, then switch to maintenance. Solving long term problems may take 4 to 8 doses.