Thanks for that link I could not find anything.
It's a 20 gallon long its been established for years
7 wmc minnows
1 hillstream loach
the danio in question is at least 18 months old. It seems more active now and the slime layer seems to have reduced a little
I'm out of the ammonia test liquid at the moment
Can't understand why it would be stressed though no new changes everyone else in the tank looks healthy
I have done a 30% pwc
and will do smaller pwc
for the next few days
I can live with loosing the one fish I just don't want this to destroy my tank.