What's Growing on/with my leather?

[Johnabennett66]

Can anyone identify this green growth near my leather? Doesn't seem to be all that invasive at this point. Was already there when I bought the leather and has grown since. Goes from green to white when the lights go off.

http://picasaweb.google.com/JohnBennett66/Reeftank/photo#5226938301679483810

[Johnabennett66]

Sorry. See the picture here:

http://picasaweb.google.com/JohnBennett66/Reeftank/photo#5226938301679483810

[greggnyce]

looks like macro algea

[illal]

definitly a macro algae... looks like this (http://www.reefcorner.com/SpecimenSheets/halimeda.htm) stuff

[nebraskareef]

illal knows the deal.

It's Halimeda

[Johnabennett66]

Yep. That's definitely what it is. Cool. Thanks, guys.

[greggnyce]

It is a good indicator of your calcium levels, good to have.