I came into lab yesterday to a disaster. I took a look at my quarantine tank and it was filled with a white bacterial bloom, the bottom of the tank was covered in what looked like leftover food and fish poop, and the water smelled like rotting fish. To top it off, the Powder Blue Tang could not right itself, and was swimming upside down and in circles. For those of you that have never owned fish, upside down and in circles is usually referred to as the "death roll." The yellow longnose butterfly fish seemed just fine though. I have absolutely no clue why there were feces and food all over the tank. I'm the only person in lab that messes with the fish and everyone knows that if they touch anything to do with the tanks without asking me, they're liable to get their hands whacked off with the guillotine paper cutter. Both fish were doing just fine when I left them on Saturday and did their daily feeding and tank cleaning. The presence of the amount of food and feces in the tank was very surprising. I do a 25% water change EVERYDAY on this tank AFTER feeding to clean up any uneaten food and feces from the night before. I'm convinced someone messed with it, because there's no other explanation. I rushed to do a massive water change. This involved making up 15 gallons of fresh saltwater, heating it to the right temperature for an hour and then slowly adding it to the tank to acclimate the fish to the new conditions. Neither fish was happy during this process and the Tang looked to be getting worse by the minute. After replacing 75% of the water, I waited an hour and did another 50% water change, just to be sure whatever was causing the odd behavior was completely diluted out. I assumed the Tang's behavior was due to either a swim bladder infection (nearly incurable) or ammonia toxicity. I left the lab to go home and figured I'd find the tang dead in the morning.

I came in today and the tang is doing fine, but the butterfly fish died. WTF!!! You can see a red patch on its side in the picture that could be a battle scar from a fight with the powder blue tang, but I've seen no aggression between the two fish in the week that I've had them. This death is very odd, I thought for sure that the Powder Blue Tang was the goner. I guess its possible that the yellow longnose butterfly fish had some other disease that was aggravated by the stress of a ~90% water change. This is one of the few things that sucks about owning a saltwater fish tank. I hate it when fish die and I don't know why :(