Large White Patches on Regal Blue Tang
I was hoping someone may be able to help me with this, I've been looking all over the internet to no avail.
We came home last night to find that our Blue Tang has large white patches all over her back. They appear to be pretty uniform on both sides. I don't think it is itch (but what do I know!) because from everything I've seen about they should be small spots about the size of rice. These are definately large patches instead.
We did not notice anything, large or small on her last night or this morning. We have had her in our tank for about 1 1/2 years. Water seems to be fine (I'll post specifics later if you need). She is eating and swimming normally.
When we first got her she would scratch herself on the rocks and that took a few weeks to heal. This kind of looks like the healing process did with that but she does not appear to have new scratches and we have not seen her scratching.
No new additions to the tank. Everything has been in it for at least 6+ months. We do seem to have more rust-colored hard algae on the glass though in the last few weeks.
55gal tank, Berlin Method filter
Got any ideas? Thanks!