Add one tablet into aquarium for each 50 gallons of water to be treated. Repeat in 24 hours. It has been suggested that a partial water change be made between treatments. While duration of the 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 for not more than 10 days. Discontinue treatment with this medication if no improvement noted within 5 days. To remove harmless yellow color, simply change 20% of water and use charcoal filter until color clears.