Terramycin (Oxytetracycline Hydrochloride) is a broad spectrum antibiotic which can be used on koi in various ways:

It is very effective against bacterial infections, especially gill rot and can be applied as follows:

1. 3 - 7 grams of the powder form / 1 kg koi food if the koi are still eating;
2. 50 grams / 10 000 liters direcly into the water;
3. It can be mixed into a paste with hydrogen peroxide, Malachite green and Friars Balsam as an ointment directly on wounds.