I was wondering if it is possible to start a marine tank without a protein skimmer. Since the skimmer removes nitrites and other nitrogen compounds, and the bacteria in the filter and the tank do that also, does that not make the skimmer excessive? I only want to raise damsels, and by the looks of their requirements, they don't need much to keep them satisified. I already have a freshwater tank, and the tetras do fine without this "protein skimming". ??? Also, when introducing damsels to the tank, should I introduce then all at once? I plan to raise 4 or 5 in a 55gal tank, and since they are highly territorial, I don't know if I should introduce them one by one.