Yellow Tang, sick or just old?

[GeorgeS]

My tang started showing these spots of discoloration the other day, not sure if its just showing age (had it approx 5 yrs) or if it's getting sick. Tank has been stable for quite some time - at least as far as I can tell. Any ideas are appreciated

 

[Nburg's Reef]

I dont think old age kicks in within a matter of days, but I'm not a fish health expert. Any system changes, eating pattern changes, new additions etc?

 

[Robink]

Mine is about 10 years old and doesn't have that. @Humblefish or @melypr1985 , they are the experts.
I feed nori daily and add selcon and vitamin c every day in their frozen food.

 

[Big G]

Redness should be viewed carefully with suspicion. Looks like it is fighting a bacterial infection. Do you have Ruby Reef Rally? A 60-90 minute bath would give the fish a very gentle dose of antiseptic & antibiotics. The next step up in treatment would be Nitrofuracine Green Powder (which works great on redness/red spots of large fish like butterflies are prone to get) or the trifecta of Furan2 + Kanaplex + Metro.

 

[Humblefish]

Has there been a recent salinity swing in your tank? Sometimes light colored fish will show red markings due to capillary congestion leading to the rupture of the capillarys through sudden exposure to higher salinity levels. Usually only happens to new fish (“acclimation stress”), but if a SG mishap occurred during a recent water change that can cause it too.