I have 120 gallon tank for only parrot cichlids. Runs off of 2 pumps that are in total able to do 250 gallons of filtration. There is 11 cichlids within the tank (roughly 4-5inch each). 1 is currently free floating upside down and on its side. I tested the water and have no nitrate or nitrites, PH of 6.5 and a GH of 180ppm. There is no signs of sunken or bloated belly. No white dots or frayed fins.Slim coats looks fine on all fish. All other fish seem to be doing fine. I believe there is something underlying do to another cichlid doing the same thing 2 months ago before passing.