My SFF has a swelling to the lower abdomen, but not on the rest of his body. He is not as active as he used to be, often just flopping down to the gravel or into the plants. I've attached a photo from the rear showing the swelling. Any idea what's wrong - dropsy? tumour? something else?
Edit: Water stats are 0ppm Ammonia and Nitrite, 20ishppm Nitrate, pH of 7.8.
Edit: Water stats are 0ppm Ammonia and Nitrite, 20ishppm Nitrate, pH of 7.8.