jlk said:As long as the product is not expired, your welcome to try it. Usually, you want to use a stronger antibiotic such as kanamycin combined with a fura antibotic for the best effectiveness. As you fish loss rather quickly, I suspect you have a much more virulent strain of flex. If you have fish that are salt tolerant, increasing the salinity to .1-.3% will help too. Heres some more info on columnaris: Columnaris (Flexibacteria); Aquarium, Pond Treatment, Prevention; Fungus, Saprolegnia
Thank you!