Add one tablet (500 mg) into aquarium for each 20 gallons of water to be treated. Repeat in 24 hours. It is suggested that a partial water change be made between treatments. While duration of treatment depends on type and severity of the infection, it is recommended that extended baths in the medication continue for a minimum of 5 days and no more than 10 days. Discontinue treatment with this medication if no improvement is noted within 5 days.