Hello I recently bought two GSP and lately one has been looking very bad. Some days he would have a white belly and be swimming around, but now he is looking worse for wear. Our other one is thriving in the tank but we put the sick one in a small hospital tank until we find out what is wrong. He us sunken at the bottom and when he tries to swim he moves upside down and ND just does side flips. I noticed that his and is also white. It is not protruding very much but it is definitely not normal. He is almost black in colour. I do belive he already came with something g because he was brown when we started off with him. For a but he was well but he's gone back to this sad state and it kills me to see him not getting better. We have gradually put them both in brackish water and put prime and medical care for them since they're wild caught but it doesn't seem to be doing anything. Please anyone who knows what's wrong help us. We love how playful he is when he's healthy but I fear he won't make it.