Contrary to what some have come to believe, you can service filters frequently to get the 'crud' out of the system. Imagine if nitrogenous waste was always removed and didn't decompose and pollute the water. Also, once a tank is established, filters can be cleaned with tap water as there is far more BB in the aquarium, ESPECIALLY the substrate than in any filter (consider the surface area in the substrate).
Finally, unless your fish load is very little, I'd do a 50% weekly water change. When done routinely, there's rarely too much fresh water.
(I have Swordtail grow out tanks that I do 50% twice a week.)