Shut or nonworking gill (once in a while)

[fowldave]

What could be the cause of an intermittently shut gill in a fish?

Every fews days (3-6) i notice either the right or left gill of my powder brown tang shuts for a few hours (2-5). The side is at random and only one becomes shut. During that time the base of his pectoral fins becomes orange too (lack of oxygen I assume). No visible infections, disease, parasite, etc...

Can anyone give me possible causes? Thanks!

 

[fowldave]

no one got any idea? Wanted to throw him into my DT cause he's been in a small QT for a few weeks already and otherwise really happy/healthy, but slightly worried he might bring something in. But then again it seems like he needs a lot more swimming space so i want to get him into DT.

I've treated him with freshwater dips with tank changes (5x), Maracyn 2 (1 week), and QuickCure (3 doses of Formalin and Malachite Green). As a result whatever this is I dont' believe is a disease, parasite, or bacteria. Plus the gill that is shut switches sides. Yesterday morning one side was shut, and the opposite side was shut in the afternoon.

Don't understand it, anyone????