Protein skimmer help??!

Cool, hows it workin for ya now? Are you gettin some skimmate in the cup yet?

 

the inner tube slides out, you have to take the o ring of the top to get the inner tube out.

here is a mod i did for it also.
http://www.3reef.com/forums/protein-skimmers/how-mod-sea-clone-55998.html

 

whats the "o ring"
and i think ive tried to pull that out already.

 

take the cup off the top, inside the black part there is a rubber o-ring pry it out carefully and the inner tube will slide out.

 

To answer your initial question. The noise was caused by the pump cavitation, which is what happens when the pump gets too much air but not enough water. By putting the valve on you should adjust it to where it gets as much air as possible, without causing the pump to cavitate (you will know if it cavitates by it making a noise similar to what you heard before). So open up the air all the way (using your valve), and you should hear the cavitation noise, slowly close it until it goes away and you will be golden (or at least as good as it gets with that skimmer, without the mod.)