Bleached Coraline algae?

[Moonrs]

I've got a small hermit crab that's been in my tank for a year. While it's been in the tank, it's shell has slowly become almost entirely covered in nice, purple coraline algae. In the last month, almost all of the coralline on the shell has turned white. Nothing else in the tank has exhibited the same problem, but I'm still a little concerned. At best, I'm just annoyed that it's shell has bleached, and at worst, I'm worried that this could become a tank-wide problem. Has anyone had this happen before, and do you think I should be (more) concerned, or is it probably an something I am over-reacting to? Thanks. sorry, no pics... Moonrs

[Instar]

Don't worry about it so long as your water is clean. Coraline grows best if the water is very clear and clean as you get when you run carbon. It sheds suface layers and also dies to become a larval stage from time to time so all you see are the white calcium deposits. So long as you haven't over done it with some additive and made that happen, it will come back. Even if you made it happen, it will still come back. All algaes cycle in some way. They have both dormant and growth cycles during the year.

[TAXMAN]

My snails have done the same thing. Turns white then back to purple a week or 2 later.

[dan]

mine do the same. sometimes some of my live rock will have white spots than color up in a few weeks.

[Henry]

I had mine do the same after I changed lights. colored back up in a week or so

[Moonrs]

Whew! that's a relief. I was worried something was going to wipe out all the coraline. I noticed there's a 2X3" white patch on one of the LR. Crossing my fingers that this is temporary...

[TAXMAN]

Even the LR will die off and shed from time to time. Different lighting or water conditions can cause it, but sometimes it does it for no real reason. It should be ok.