What is this white mold?

[lyscer]

I noticed in my overflow I have white mold looking stuff above the water. It showed up about a month ago and hasn't really gotten worse but I'm wondering what it is.

 

[lyscer]

You can see it in the corner of the tank and then more on the drain pipe.

 

[evolved]

salt creep?

 

[lyscer]

It doesn't appear to be salt creep. When I get home I will use a razor blade to scrape it off and will put it in water. If it dissolves I will assume salt creep. But it doesn't look like normal salt creep.

 

[evolved]

I just can't imagine any type of mold growing in nearly a brine environment.