Ampicillin is a wide spectrum Anti-Fungal/Anti-Bacterial Antibiotic. It is effective against gram-positive and gram-negative organisms. Ampicillin has been shown to be effective against a number of pathogenic bacteria associated with ornamental fish diseases. Use For: Infected Eyes, White Body Slime, Popeye, Columnaris, Fungal Infections, and Advanced Fin and Mouth Rot. Ampicillin is an effective, colorless aid in Marine and Freshwater aquariums for fighting Bacterial Infections of fish. Use as directed is safe in the community tank and will not affect biological filter beds