Algae in overflows

Well, I was working on my 2 month old 120 gal All Glass Reef tank when I noticed a load of algae in the overflows. I can't believe it has grown so fast in there.
What should I do? Clean it out? Leave it alone? Is is part of the biological filtration? Or, Is it bad? Here are some pictures of it. Let me know if this is normal.

 

I say clean it out. It will absorb some phosphate and nitrate from the tank but it also cuts the flow down of the drain. Consider it a ghetto version of exporting nutrients from the tank that algae likes, sort of like a fuge.

 

Uggh! Wow what puke! I cleaned it out. It was basically hair algae in there. I can't believe it accumulated like that so fast. It looks 10 times better now.

 

AGA overflows have a rubber grommet like that slips over and onto the plastic overflow where that algae is growing onto slid that off and clean it as needed actually that algae is helping to export DOC's in that high flow and saturated oxygen area just clean it as needed nothing to worry about .. That double wall is a simple mono flow system , as that water passes over that area it creates lower pressure and then the water is lifted from the lower parts of the tank through that double wall column .

 

That concept has been employed by me since I set up my 125 gallon and few years ago. I would not use microalgae like hair(derbesia etc.) but other forms of algae that are beneficial like macroalgae.

 

I cleaned out the overflows and the tank is doing much better. These overflows are not on the corners so they don't have the inserts that come out to clean. The fronts are solid so you can put rocks up against them and not have an avalanche if jarred I guess? They are 10" wide each so that makes sense. Anyway much better flow and the water cleared up nicely. Take a look:

 

Yeah. I will be monitering mine weekly and cleaning it out. That algae can grow super fast in the overflows and REALLY clog things up! Tank looks amazing.