How to clean the body of a skimmer?

[GothFishKeeper]

I’ve only cleaned this in tank nano skimmer once since I set up the tank 5 months ago. Ever since cleaning it that one time, algae has been steadily growing in the body of the skimmer, and I can’t get to the inside to clean it. I tried rinsing it with vinegar, but that did nothing. Does anyone have this problem and/or know what to do about it?

 

[danreef55]

Use a bottle brush