What am I looking at here?

[GR00VY]

Tank is over 3 months old. I went through the brown diatom phase and that cleared up and then this green started a little while ago. I suck some out of the sand bed when I do my water changes but it just keep coming back.

 

[Doctorgori]

green and short= good ; green and hairy = bad
either way your tank is still young, I personally wouldn't worry about it at this stage

 

[GR00VY]

Just green and short. No hair that I can see.