Any experience with localized bleaching on clam mantle?

[cprowler]

I have something similar on my baby maxima I got a few weeks ago. It looks like it's healthy but this is my fist clam so I'm not sure. It is more to the sides than in the middle and I have more of it. The lighting has obviously changed coming to my tank and I have had some issues dialing in my CA reactor. I will post some pics later when the lights come on.