the color of my water
 

my protine skimmer is skimming dark dark green sluge. and others i have seen it is always is lite brown color and it is not so thick. but the water that is in my tank is really clear i dont understand.

You skimmate is more concentrated than those others you've seen. Whether this means it is because you have a more efficient skimmer or because you simply have "more stuff to skim" I can't say, but, you say your water is nice and clear that tells me it's more likely that you simply have a better setup going as far as your skimmer is concerned. It's doing its job. :cool: HTH

Crazy, ain't it? :lol: Sounds like your skimmer is working well though. Are you cleaning it often? Once a week is a good marker.