Bubbly Algae on Sand?

[Marcus Rogers]

I added new sand to my tank(the tank has been running for few years), specifically CaribSea Arag-Alive Fiji pink. I am growing some algae on the sand that is like green/brown and has some bubbles on it. My ammonia is 0, nitrate is about 5, phosphate is about .25, nitrite is 0. Here is a picture

http://tinypic.com/r/amy44o/9

So I was wondering what it is and what I should do.

 

[Gonebad395]

Cyno?