Glancing Blue Hippo Tang

[RockDoc]

Our Blue Hippo Tang has started glancing (aka Flashing), which is rubbing it's sides on the rocks. The tank is 210 gal, and has never had a problem before. The tang spent 3 weeks in QT before being put in the DT. No other fish has a problem, and the tang only rubs occasionally (a few episodes per day at most). So my question is this: are there any other reasons for a fish to start glancing other than infection? Can they do it just to scratch an itch or for comfort? Our LFS says some fish do some "comfort scratching," but I worry because Blue Tangs are the Kings of Ich. We certainly can't catch him at this point, in such a big tank with over 200 lbs of rock, so re-quarantining is out.
Thanks as always, Jay

[Amphibious]

Jay,

It's hard to say what's causing him to scratch. They do get "itchs" they need to scratch now and then. Watch him and let us know what, if anything, shows up. Do you happen to have a UV on the system?

Dick

[RockDoc]

I do have a UV. I have to look up the actual GPH, but I estimate that it runs at around 100 GPH (I could be way off). Yesterday, I only saw the Tang scratch once. Maybe he's OK. I'll keep y'all posted.
Thanks, Jay

[Pescaiolo]

Mine does some glancing as well. I can't see anything wrong with him physcally and he eats and swims happily. I think my yellow tang has hemorrhoids because sometimes he looks like he is trying to scratch his butt! They look healthy and eat like crazy they just glance sometimes. I have noticed them glancing to break algae loose from a rock, they don;t really touch the rockl(they come really close) and swim fast next to it. I think they can't reach some hard to get to spots on rocks so they create water movement to break it loose. Just a theory not sure if its a natural behavior. Hope its nothing serious!

[Rob]

same here, i have seen many tangs exhibit this behavior, you only want to watch that thy don't scratch there skin, as that could lead to infection.. mainly, just keep an eye on it fish, but its likely nothing to worry about

[RockDoc]

Thanks for the responses. I feel much better about it. It's amazing how encompassing our hobby can be; the tang is all I could think about for a couple days. Is that pathetic? Anyway, he is swimming happily and feeding well and harrassing the wrasses (yes, he's a wrass-harrasser), and glancing once or twice a day. I'll post if things change. Jay