Hello Guys, I need your help or suggestion on the mentioned topic as I am new to fish keeping and have 55 gals tank which has Oscar, Dolphin, Geophagus Red hump and Albino. Yesterday night I noticed that upper fins, tails and lower fins of the cichlids are turning black, though the fish is healthy and active. I did some research and saw few posts around it, did partial water change in the tank and added Aquarium conditioner from Seachem. pH level are between 7 - 9 but not sure why the fins are turning black. Any help or suggestion to avoid further damage to fish will be highly appreciated. I dont have the photos right now, but will post once i am home. Thanks