Many skimmers will send an unreal amount of bubbles into a tank if the water is not balaned. They can get so bad you can not see. If you add chemicals which play with oxygen amount or sality or PH you name it. In those cases they usally turn to the normal amount, each skimmer is different, when the water balances.
You need to balance the air and water intake so that you get enough bubbling to gather waste. Too much water will send bubbles into the tank, not enough water will not create enough force to shove bubbles up into the cup. Play with it. You will know your skimmer better than any of us by the time you get it fixed.
I have the Coralife Super Skimmer on my tank and have noticed that every time I do a water change, the skimmer either fills the collection cup up in a couple of minutes or will pump my sump full of micro bubbles, which usually end up in my main tank. So, I would have to say that skimmers working with new or 'unbalanced' water as was pointed out before is not a good idea. I eventually learned to not use the skimmer for two days after a water change and all is good from that point forward. I wish the people I was asking about this problem a couple months ago could have pointed out this info to me!
I like the skimmer I have because it has a little 'tuning' knob on it that I can control the amount of water and bubbles in the main chamber. Basically, I can make it run faster or slower depending on if my collection cup is being filled with dirty water or clean water with the obvious goal of only getting dirty water out. Sometimes my skimmer will overflow during the night too which is bad for the carpet but luckily it isnt fast enough to drain the tank like i have had happen with a filter on a FW tank once!
I also know that there is a spacific location that is best for a skimmer in relation to the water level (top). I havent really figured this out yet so if anyone could point out where this information can be found in a reasonably easy to follow manner, maybe all of us newbies can learn something! :bowing: