hi i noticed that one of my fire mouths tail has gone black. 
dose any one know what it is. could it have anything to do with treating white spot 
as i have restocked my tank over the last 5 months and must have got it from new fish, the tank has been running for 4 or 5 years with little probs. i have 2 young fire mouths, 2 young kribs, 8 guppys, 7 neon tetras, 3 small brisle nose plecs, 3 sail fin mollys and a angle fish.
the tank is very peacefull
25%ish water changes weekly
Tank size:120l
pH:7
ammonia:0
nitrite:0
nitrate:40
kH:dont know dont have test
gH:dont know dont have test
tank temp: 26
other fire mouth
dose any one know what it is. could it have anything to do with treating white spot as i have restocked my tank over the last 5 months and must have got it from new fish, the tank has been running for 4 or 5 years with little probs. i have 2 young fire mouths, 2 young kribs, 8 guppys, 7 neon tetras, 3 small brisle nose plecs, 3 sail fin mollys and a angle fish. the tank is very peacefull
25%ish water changes weekly
Tank size:120l
pH:7
ammonia:0
nitrite:0
nitrate:40
kH:dont know dont have test
gH:dont know dont have test
tank temp: 26
other fire mouth
