what killed my BN ?

[jonnybryan]

ive got a breeding tank of BN , Any idea what killed him or why he turned white??

 

[D-MAC]

Can you give us more info? Tank size? how many fish and what are they? How often do you water change, and by how much at a time? Have you done any water tests for ph.nitrite,nitrate and ammonia, if so what is the readings? Whats its diet, and how often do you feed?
The more info we get from you will help us to determine what the most likely cause will be.