Hang-on over flow box help

[Jcearl]

Hello all, I have a CPR cs202 overflow box - BUT mine is an older model that have a clear top which algae has stated growing on the top and clogging the top to where the aqua lifter sits. is there a way to clean it? thanks for the help?

 

[Cory]

No idea, maybe post a pic of the problem. Fwiw hang on overflow is cheap.

 

[Joeganja]

Vinegar