Good or bad green algae?

[Aparker2005]

Hey everyone. I've been feeding more nori with tangs and angels the last few months. Part of our filtration is 2 Seachem tidal filters. I've been noticing this green stuff growing on the outflow all the way across. Is this good algae, or just a sign I need to be cleaning more often? Thanks!

And sorry for the blurred picture :(

 

[Mr. Mojo Rising]

Its a sign that you need to clean more often