Help with overflow cover

[Damion123]

I have some algae growing in my overflow and I want to make a cover to block out the light spill. Any suggestions on what material I can use that is easy to work with? I have an innovative marine with the coast to coast internal overflow, so the shape is not just a simple rectangle.

 

[Harpo]

A piece of black acrylic would be a good place to start. Although it may warp if not reinforced. You could also 3d print a lid. If you give me the dimensions I could draw up one for you in Fusion 360

 

[Damion123]

I was thinking about acrylic. The IM over flow has an unusual shape so don’t know how I would cut it. I don’t have a 2D printer either.