Lost 2 Fish in 2 Days ??????????

[Black Phantom]

It won't be an oxygen issue at I have a huge water turnover through my sump as well as two Tunze pumps in the tank itself. And from experiance it takes about a week of really hot weather around here to bring the tank temp up and that hasn't happened. Temp is right on 79 as usual.

I think if they had eaten bad food then the rest of the tank should be showing some stress as well. So far everything else is ok. Checked on them the first thing this morning and my other Tangs are fine. I'm wondering if I got an ammonia spike from the first one passing away. If my Foxface was a bit weak then that might have been what did it to him.
Who knows