Tito...set it up anywhere you like, but the filtered water has to run somewhere. Most people run it into a tub, or 45 gal. rubber trash can. It depends on how much water you are making per day/week. You can run it straight into your tank, but unless you are monitoring constantly, there will be no way to know how much you are putting in. Your best bet is to run it into a tub or trash can, where you can save it and manually add it to your tank as needed.