The only thing that you NEED to do is make sure the water is clean and clear with plenty of oxygen, and there is a good supply of food. However, I personally add salt as I have found the cichla's to heal faster and it takes care of any bacteria that might upset the wound. Depending on the species of cichla, they can range from very sensitive to water conditions(intermedia) to very tolerant to a wide range of conditions (Mono's). Since you have a Mono, what you do should be based on what you are comfortable with and not just what others tell you they do. Good Luck on the healing!