Like vamp said, just watch nitrates to see how much to drip. Thing is, the more water you drip, the quicker your carbon filters need to be replaced. I'm planning on 40 GPD on my 540 Gallon, so I think you'll find that you only need to drip 20-40 GPD. Ya figure 40 GPD, that's 280 gallons in a week. That's almost your entire tank volume every week. I'm guessing if you just replace half the tank volume, that's plenty.
I don't know, though. My 3 stage chloramine block filters just shipped from Filter Guys today, so I haven't set mine up yet. We'll compare notes later!