Another Algae Question

[DirtySubstrate]

I'm hoping this is similar to Seacats post "Algae Outbreak", but I cant tell from his picture.

My Tank has been running for a little over 4 months. Over the last few weeks I have noticed a ton of what I am assuming is a brownish colored algae building up on my live rock. Is this typical or a sign of bad things to come? What's a good critter that can help control this?

I also noticed that on the base of a couple of my larger rocks it appears that it is turning a very bright lime green color. Is this an algae?

 

[Cafe Jeff]

I am having some of the same behaviour in my 20 gallon.
Have a cleaning crew and some live rock but no livestock so not overly worried.
Perhaps I should be?
Jeff

 

[klam]

I also noticed that on the base of a couple of my larger rocks it appears that it is turning a very bright lime green color. Is this an algae?

This can possibly be coraline algae which comes in many different colors like purple, orange, rust, green, maroon, etc.

Might be another diatom bloom that you are having. The major algae to worry about is cyano and hair algae.