there are lots of medication options. check with your local lfs to see what they sell. one option is to try dipping the undulates food in selco, garlic, or some other vitamin supplement. that will help with the immune system. Maracyn 2 is often used for bacterial infections which I think is what your undulate has. if the lfs has freshwater Maracyn 2 just double the dose. Other options are nitrofuran or kanacyn.