Something appearing on my Leather

[the_bandit]

Started out small about 2 weeks ago and is spreading. Not sure what it is. Ive heard it could be a parasite or something. Need info please. Thank you.

 

[marchingbandjs]

Looks like ich for corals...
I googled and some people have bleaching but that dont look like bleaching.. Did you change lights...
there are a lot of things it could be...

 

[t316]

I had some salt buildup above my tank once, and when I was cleaning it off, a small chunk fell in the tank. I noticed a couple days later that a coral just below this area was bleached white, most likely from the encrusted chuck of salt that landed on it. It eventually dissolved and the coral was fine, but looked similar to this.

 

[roxannej]

It looks like it's getting ready to shed. My toadstool always looks like that the day before it starts shedding.