This is definitely a question many of us has had come across our minds. I know both is best but what if you had to choose between the two, which would you choose? Right now I'm stuck with this dilemma. As you all know I have added a frag tank to my main system which now is totaling about 90-100gs. My old skimmer is not cutting it anymore. I have a larger skimmer rated for 200-250g (I know its huge its ment for my upgrade) but it will only fit in my sump if I remove the refuge section of the sump. My chaeto doesn't seem to be growing but not dying either. I have added fish to the frag tank as cleanup crew so that's where the added waste is coming from. Let me know what you guys think.