Yes, the waste water is significant, but I am on a well system, so I can afford to use a fair amount of water, because it only costs me the electricity to pump it.
I got the larger accumulator tank to accommodate storage as Martin indicates. Since I don't have it yet and haven't got an actual result as yet, I have to say YMMV to the max. I would possibly feel very different if I was paying a lot for my water.
I will keep you posted, Amanda, but I doubt that I will have this installed and running until later in March.