Love your setup, Mark, and I am jealous of the size and headroom in your greenhouse. My backyard neighbor would shoot me if I had something that tall. Guess that's what happens when you live in town.
How are you capturing your rainwater? I have been thinking of putting gutters on the greenhouse, but I really don't have any room to put a tank in. I also have access to irrigation water all summer, but once again, no tank.
Cheers,
Carolyn