Marineland Penguin Nitrate Filter?

[jgiannini]

So I'm curious, rather than having a second pump in my tank for a nitrate sponge filter, has anyone tried using something like a Marineland Penguin Power Filter 100B for the same purpose? Just take the filter insert out and drop in a media bag with the nitrate sponge? I've been trying to get my nitrates down to 0, but they seem to keep hovering between 5 and 10. Thanks.