For this product we require a completed Drug & Chemical Affidavit on file. If you have not submitted this form to us, please click here, and fax (813-671-8237) or email (fishsupplies@verizon.net) back to us. Thank You. Bacterial infections- It is important to remember that pathogenic bacteria are always present in our water and on our fish. They are a problem only when the fish are weakened by poor water quality or parasite infestations. So, before attempting to treat a bacterial infection, be sure that you correct any underlying problems first. Symptoms can include fin and tail erosion and fraying, redness of the tail, pectoral or anal fins, and red open sores (ulcer disease). The most effective remedy for most bacterial infections is feeding medicated food containing tetracycline, romet, or oxolinic acid for 10-14 days. Ulcer disease- Ulcer disease is a particularly destructive bacterial disease. Seen on koi and goldfish, it starts out as a red or white pimple and quickly widens into a large hole or ulcer. It can advance all the way into the muscle of the fish. It is very important to catch this disease in its earliest stages. Anchor worms, fish lice, and flukes can all contribute to ulcer disease. Keeping your fish clear of these parasites is very important. Keep affected fish in salted water and feed medicated food containing oxolinic acid or romet. Info from WernersPonds