Looks like 2 types of algae which possibly could be changing the appearance of bubble algae colour to brown.

It could be diatoms and bubble algae on top of it.

How old is the tank?

What are your nitrate and phosphate levels?

Emerald crabs eat bubble algae or you will need to carefully remove it without puncturing it.

That's better. What happens if you hit it with a jet of water, like with a turkey baster? When you pick it off the rock will it burst like a balloon if you squish it between your fingers? Is it kinda slimy? It's certainly not typical green bubble algae, but it may be red bubble algae (Botryocladia skottsbergii). Red bubble algae gets rusty brown/reddish spots on it and lightens up as it matures and will look more brown than red. When it is small and more maroon red it is slimy, but isn't slimy when it matures and gets the spots/lightens up. Nothing that we typically keep in our reef tanks eats red bubble algae.

http://i86.photobucket.com/albums/k9...lealgae003.jpg

http://www.saltcorner.com/Books/Book...201%20(BG).jpg

tank finished its cycle mid March, but water has been running since beginning of Feb I believe.

according to hanna kit, phosphate is 0. I am picking up another ki today to compare to the hanna kit.

haven't tried shooting water directly at it. I have tried picking some off rocks. compared to green bubble algae which was super firm and easy to pick up, this algae was super soft upon touching it. in fact it got punctured every time I used a scalpel or tweezer to remove it from the rock. I tried to see if it released anything into the water as I removed them from the tank, but I did not see anything. im starting to winder if there is anything inside the algae as some of them look deflated and are pressed down on the rocks.

I was debating removing all the rock and starting from scratch, but it was suggested I would have to rehouse my fish during that time, which is a no go since i have no where to put them.