Ciprofloxacin is a synthetic broad spectrum antibiotic that is effective against gram-negative and some gram-positive bacterial pathogems of fish, e.g. aeromonads, flexibacteria, vibrios. Use for: Columnaris infections (Fin Rot, Saddleback, and Black Patch Necrosis Syndromes), Freshwater and Saltwater Furuncolosis (skin ulcers, systemic disease). Because it inhibits unique target enzymes needed for bacterial replication and DNA repair, it may be effective against bacteria unresponsive to other antibiotics. DOSAGE & ADMINISTRATION: Add one tablet per gallon of water in the hospital tank for a 1-hour immersion bath. Add crushed tablet to some water, then add this suspension to the hospital tank. Repeat every day for 5-7 days with daily water changes after each treatment. Ciprofloxacin chelates divalent cations water hardness (increase dose for marine fish) and high divalent cations in diet. Its activity decreases with high pH (>6.9). It can be bacteriostatic or bactericidal depending on the effective concentration at the target site.