Background: 29 Gallon tank. Have had the thank for about 6 years. Had two orandas and nothing else. Recently had one oranda die suddenly. No indications of anything wrong. Was eating and acting fine then an hour later was dead at the bottom of the tank. Thought he may have choked on a rock...really have no idea. Had no external symptoms. Added a smaller oranda recently, neither seem to be bothering each other which I was a bit concerned about. A few days ago I noticed some red streaks in the older ones fins and now it has white puffy stuff on it. I tested ammonia and it was fine (out of nitrite test at the moment, need to buy more). Any help with identification and treatment is appreciated. Let me know if you need more details. Here are some pictures: