overflow cleaning question

[StephNewman]

I have internal overflows, should I be cleaning the algae out of them or just what grows over the slits, should I take the pipes out and clean them ever so often or just let them be.

 

[DrBDC]

I occasionally scrape out some grunge. My current tank has the overflows on the end so I guess I'll be siphoning detrius now too. A cover over the top so that it doesn't get light helps a bunch.

 

[sirreal63]

It can also be a free algae scrubber.