i have a 50 gal tank with 6 lemon tetras, 6 black skirts, 1 paradise blue gourami, 2 white tip blue sharks, 3 lace synadontis, one small black ghost knife and 6 ghost shrimp. i do my water changes one a week, everyone is healthy except i my largest synadontis has a white spot on its side that is 2-3 cm, this fish is not showing any signs of distress no rubbing, swimming normal, no pinched fins, as with the rest of my fish in the tank. could this be a parasite or just a possible wound. i bought a general cure anti-parasitic medication by API, is it safe to use? i don't have a quarantine tank i just don't have room for one.
and if advise you have is greatly appreciated
i attached a photo it is really blurry but its the best i could do with my camera