fish doxy doxycycline 100mg Tablets 30 count  Description: fish doxy doxycycline  is useful for control of some common bacterial diseases in fish, including Septicemia, Mouth Rot, and Fin and Tail Rot. This product is USP grade and manufactured in the USA Active Ingredients: Doxycycline Hyclate 100mg Directions:  Add 1 tablet (100 mg) into aquarium for every 10 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 infection, it is recommended that extended medication baths continue for a minimum of 5 days but not more than 10 days. Discontinue treatment if no improvement is noted within 5 days. To remove harmless yellow color, change 20% of water and use charcoal filter until clear.