Why is my skimmer going nuts?

[jason604]

ok this skimmer is rly stressing me out.. it literally takes only 1 hairline of a turn for it to overfill like mad or bubbles to drop all the way down. when i do find the perfect spot it will work great for like 5-8 hrs then when i come back to look at it the bubbles drop all the way down again... what am i doing wrong? i raised the skimmer another 1' so its at 7" of water now and i have to tune it to nearly a fully closed air tuner for it to have bubbles near the top of the neck which i normally have for my other tank