I agree with the others; also, in a FO or FOWLR, you tend to have greater bioload and lots of fish waste. Filters like wet-dry are efficient "high load" processers of ammonia and raw fish waste. As has been mentioned, the end product, nitrate, is not as big a deal in these tanks, as it's not really toxic to fish (but not good for most corals). Personally, I like the one-two punch of adding a skimmer to a high load mechanical/biological filter also.
Hey gravey, it's Feb 14 & not too late for that dinner! :inlove: