I have been researching a lot to figure out my protein skimmer, don't know what kind it is, I'm totally NOT mechanically inclined, couldn't grasp the concept of how it even works. Tonight my husband found a flow adjuster that sticks into the air intake tube. I just saw it laying in bottom of my tank cabinet, didn't know what it was for. Duhh!!! Now I'm lookin in threads to find out what the flow adjustment should be. I guess I'll take some pics and see if someone can ID the type of skimmer it is. The inherited tank didn't come with manuals or anything, I've just researched and asked questions to figure out what things are and how they're supposed to work...I do much better with the chemistry side of things!