Algae in skimmer concrete cover

[Davegnh]

I am seeing some algae around my skimmer this is an area above the water line and is open to the atmosphere and has a mix of foam and plastic still in it so very hard to clean. Any recommendations on how to take care of this?

Maybe some sort of paint that would stick to the plastic that would stop light from getting under the cover?

 

[AQUA~HOLICS]

Very common with pour-a-lids, find a way to inject chlorine to kill the algae then seal after words with a silicone.