protein skimmer help

[Alowery76]

My protein skimmer is not working right. It does not foam at all but the pump is running water threw it just fine. I twist the air valve and nothing. Cleaned it out and still nothing. Any advice would help

 

[JumperAlex]

What kind of skimmer is it?

 

[Alowery76]

One at petco, had for a couple of years. Ocean reef or red sea, something like that