A second skimmer is almost always a very good idea. Regardless, you shouuld be pulling a full cup of skimmate out of your tank every day. If not, clean and tune that skimmer(s) better. And don't believe your tank does not have enough organics for it. I didn't believe it either until German friends pressed me hard enough to really learn my skimmers. I have gotten daily skimmate out of 240 gallon culture tanks with Xenia only (no organismal feeding) and no fishes! Just snails for diatom control and yes... daily skimmate produced. Amazing. As for water flow, the rough rule is 30-60X turnover... but simply apply as much needed to keep all solids in suspension. If you see solids settling, you need to tweak the currents so that does not happen. For any more questions, my friend... could we please take them to the general forums so that more people benefit from our time and discussions than just us? Its good for everyone that way. Kindly, Anth-