If your water does not have chloramines but only chlorine, then you can age your water by leaving it out in a bucket over the week. But for tanks larger than about 10g this isn't a really viable solution.
If you felt like doing a ton of construction, you could set up several large rain buckets a floor above your tanks for aging water and have a water line running through the floor to the tank(s). Again, clumsy and cumbersome and only possible if your water company doesn't use chloramines. Compared to adding a few mL's of conditioner every week!?