Yellow watchman goby trouble

[JMM744]

120 with two large hob filters and a powerhead pushing water at surface. Been a week in copper which is copperpower. Hanna reads 1.57 to 1.60 so just over therapeutic level. Was eating thru thurs. Fri. It moved out of its place of concealment to the far side of the tank in the back corner and did not eat. As of this morning and tonight it is laying the corner breathing pretty hard. Ignores food completely. I will give it fresh water dip tomorrow but don’t see anything wrong with it. Two tangs, purple dottyback and black scooter blenny are just fine. Any thoughts about what might be going on? I seeded the sponges before starting the system so don’t expect it’s amonia plus other fish are not affected. Thanks ever so much,
Jim

 

[EmdeReef]

Was the fish sick before you started treating or just treating prophylactically? If it was showing symptoms, what kind? Can you post pics?

Was it eating before copper?

 

[JMM744]

Treating because a striped blenny showed signs of velvet. Yellow has eaten quite well the entire time in copper. I hit therapeutic level in two days. Been almost a week in therapeutic level copper and it ate quite well till Fri. No visible signs of anything.

 

[JMM744]

Did freshwater dip. Noticed nothing. It wants to stay out of the flow so is laying bight to an area where it’s blocked from it. Still no food but looks fat enough.