Excuse me folks, but im like one of those who doesn't believing in those items called phosphate and nitrates sponge, For a matter a fact, I believe they may help somewhat, but never expect a lot from them for the major work in all this, comes from the hobbyist themselves. One need not to over stock and feed for one thing. Also we need not to buy something that will outgrow our tanks, meaning more so that it be the only fish left in the tank.
The main and old fashion way in doing this is in water changes, This of course would differ from one tank to the next. For we also not do all the same in our tanks maintenance so water changes in amounts and how often can and do differ from the next.
I knew one person that did a 40 gal water change on their 150 or 180 reef tank a week. The thing was, they were over stock and over feeding. So depending on your tank size on stock and feeding you do, you might need to do a bit larger of a water change, besides, you failed to mention what size tank this be.
I'm in plan to possible start with a 10-12 gal water changes a week on the 180 and a 15 gal on the 240. I would make any adjustments that might be needed when I do my water test. Also when feeding, feed in little amounts and wait until those offerings are not visible. Also with many species in reef tanks, some need to be feed twice a day, this would only add to ones problems if not taking care of.
musho3210, sorry but I agree with Germanman views on the carbon issue>