Help! there's a white patch on my fish

[mariann369]

There is a strange, white patch on my boxfish. I noticed it the other night as just two, small, white patches on its back. The following morning, it nearly covered my fish's back. I attempted to take the fish out of the tank to do a freshwater dip and when I did, ALL the white stuff fell off its back. It looked like a patch of dried baking soda. I thought the fish was better, but now it's getting small patches again. If anyone could help me identify what this is and how to treat if, I would GREATLY appreciate it!
Thank You!!

 

[mariann369]

Thanks, but the fish didn't make it. It didn't respond to the freshwater dip. It's flaky stuff fell off it's back when I caught it to take it out of my tank. It was the weirdest thing I've seen, and even had my LFS stumped.
thanks for responding..
Mari Ann

 

[clarkiiboi]

I had (what I think) is the same thing on one of my fish, it just overcome it and continued, I felt so bad, did hypo but didnt get a chance for antibiotics and then too late. I have been searching for what this is and no results yet. Sorry about your loss.