If you’ve never had your fish get sick don’t do what I did. I always figured my fish would not get sick because I always kept my aquarium well maintained. I always did a water change at least a partial water change each week. The fact is no matter how well you maintain your tank your fish can pick up a disease and it can be devastating! The last disease that plagued my fish pretty much wiped out my fish population. To reasons, one I didn’t recognize until it was plaguing more than one fish. Two because I didn’t have the medication they needed on hand. Read more about the diseases and pick up preventive medicine the next time you pick up fish tank supplies