By the time you get to the wastewater point you have ran it through probably 3 filters, 2 to reduce sediment and one to remove chlorine and other contaminants. It is waste water to the fact that it isn't what you want to use in your tank but it is cleaner than your tap water.
So get some of the empty 5 gallon jugs at walmart and a small water cooler, then you can have better water for your household and great water for your tank.