Huge!! Oh that's soooooo good for you guys! I wish we had town water available though it will be a long while away for us. Though I sort of love the idea of living off the grid one day - with solar also.
I know what you mean! We will put in a tank or 2 and plumb in the washing machine and toilets. We did that for our last build and it felt good to know the rainwater was going to good use. We didn't have time to stuff around and sort out a smaller tank as it was contract signing day. We are getting solar and hubby looked into getting batteries but we just can't afford it right now