I'm with these guys, it really is acting like a water distillation. I think
bob is right, watch it if you add any stuff to the collector, but other than
that, i think it would work great.

how do you intend to use it? Maybe pipe it into a plastic water drum so you
can collect it 24/7 and use it as needed?

I don't seem to be having ANY drought problems here in alabama--do you need
like 6" of rain? (it's ok weather if you're a duck!)
later
john