FIX CEPH 500 (Cephalexin or Keflex), is a broad-spectrum antibiotic that is particularly effective against numerous pathogenic bacteria that cause diseases in ornamental fish, such as infected eyes, tail rot, gill diseases, and skin ulcerations. The recommended dosage is adding the contents of one capsule (500 mg) into the aquarium for every 20 gallons of water. Repeat every 24 hours, with a partial water change between treatments. The duration of the treatment is based on the type and severity of the infection, ranging from 5 days to a maximum of 10 days. If no improvement is observed within 5 days, discontinue the medication.  This antibiotic should be kept out of reach of children and is strictly for aquarium use, intended only for ornamental fish and not for those designated for human consumption. The product should be stored with the lid tightly closed at a controlled room temperature of 59°-86°F (15°-30°C).