I must wonder if I have the ONLY oregano medicated fish in the world!
The tank is 160 gallons. I often put 2 drops of pure oregano in the water. I know the average person in a bathtub can feel the oregano oil at drop. You can only imagine how the fish feel, yet I see no ill results.
i do not know if the oregano would work, it would be an experiment.
how much? no one knows, again, all experimental and don't do it with any fish that you an't live with out, because you may not know the results until it is too late!
rectangle standard fish tank, 5 feet by 2 feet by 3 feet tall. They had them on 50% off sale last year. I assume the best way to trick you into buying fish, is to first get you to buy a tank..