[slief]

Originally Posted by slief

Close the wedge pipe some to get the water level up to about 1" below the white PVC collar at the top of the body. Also, you may want to loose the set screw that keeps the wedge pipe tight and make sure the wedge pipe is seated all the way down into the effluent fitting. If it's not all the way seated, the wedge pipe will not function and you won't be able to raise the level in the skimmer.

How long has the skimmer been in the sump? I assume you have it in salt water and not fresh water for testing?

Your wedge pipe must not be seated all the way in. Closing the wedge pipe by rotating it blocks the flow of water coming out of the skimmer. The more you close it, the higher the level inside the skimmer. If the skimmer is responding to the wedge pipe then it's not all the way down into the fitting. Like I said, loosen the screw and push the wedge pipe down all the way into the fitting. You can pull the skimmer out if you need to and inspect the wedge pipe so you can see if it's all the way down and familiarize yourself with how it work. if the wedge pipe is seated, it should be able to make the skimmer overflow because the water won't be able to leave the skimmer.
The reason holding your finger over the air intake or placing the hose on the ozone port works is because you are reducing the airflow into the skimmer which in turn increases the water flow. The wedge pipe is your friend. If need be, raise your sump level a bit higher. If you are at 8", raise it to 8.5".