Yellow Tang getting red spots

[rzelred]

Can someone help me? I have managed to maintain a saltwater tank for the last eight years but I consider myself an amateur. I have three yellow tangs. The oldest and biggest tang has had red spots on the rear half of his body for 3 weeks. Now one of the smaller tangs is also getting this. I do a 35% water change monthly and did one a few days a go.
The rest of my fish are; 1 blue tang, 5 spotted puffers, 1 hawk fish, 2 tomato clowns and 2 percula clowns.
130 gallon tank with CC,
wet dry filter
fluval 403 filter
berlin protein skimmer sits in wet dry filter sump.

 

[dburr]

Did you post this in the desease forum? They are really good over there.
Welcome to the board. Sorry I can't help you. It sounds like maybe a parasite.

 

[barracuda]

First of all there is nothing to do with the water changes. You are probably talking about black spot decease. The color of spots is dark red. Yellow tangs are used to have this kind of decease from time to time. Mine had this before. What i did is fresh water dip for 5-6 minutes and the spots desapeared after about six minutes and never came back. U need to make temp and PH of the fresh water the same as your main tank. This is just from my expiriense.
Good luck!!!