You are pretty much correct. I still find the changer helpful and although expensive. I didn't get one yet because I would need something like 40ft long. Instead of adding the tap water directly, you can use the changer to add water to your tub. My water storage tub is next to my tank and my tank is some 30 ft away from my kitchen sink. And some 40ft away from the bathroom. So, I have been using a 5g bucket to do my WC.