Starting over with my tank!

The principle of skimming is for the body (reaction chamber) to fill up with lots of tiny bubbles. By adjusting the water level (usually the exiting port), you can raise or lower the foam to the point where you want it to maintain its height. Some skimmers, the foam should be bubbling right at the base of the neck / riser tube that leads to the cup. Others, you want it halfway up the riser tube. Some keep it bubbling within 1" of the inner ring inside the cup.

If it is set to skim wet, with the bubbles very high in the skimmer, the skimmate collected will be very watery and relatively clear with a little tint like tea. The risk is that it will overflow the cup all of a sudden, which can make a mess -- especially with an external skimmer or a HOB skimmer.

If the skimmer is set to skim dry, the cup collects very little liquid and the neck / riser tube usually builds up a thick slime of skimmate. The bubbles are further away from the cup, which limits how much can be exported.

What you want to do is find the sweet spot for your system. I recommend cleaning the cup and riser tube often. Daily is best, but at least every few days at the minimum. Otherwise if the skimmer does overflow for some reason, you don't dump all that waste back into the tank, or elsewhere!

Thanks for the info Melev, I will play with it, and clean it like you say. I never had a skimmer before. This might sound crazy because I don't know how fast they suppose to work but my wife and I noticed a difference shortly after I installed it, a few hours.

With a skimmer, particulates stick to the bubbles and are pushed up into the collection cup. The water's clarity should be improved.

Ok, yeah it improved a lot with the skimmer. Thanks