Yes a water change weekly is recomended either aged or with chlorine remover, but in so saying that i have seen some tanks that are apsolutely disgusting, hardly never had a water change. The fish in the tank were fine, i would go as far as saying that they were better than fine, they looked really healthy.
I wouldnt recommend doing this, but it goes to show that fish are a bit hardier than we think( well than i tought ).
My brother has a tank of community fish, and when he does a water change he never uses aged water or water ager, its just straight out of the tap, his fish are fine and breeding.
Something to think about