Regarding the Fish Air pump, you might not want to waste your time. I set up a similar system for my rabbits, heater in bucket, attached a pump to circulate the water through the pipes, even put heat tape over all the hoses, but since there is metal on the nipples, it would still freeze. Maybe...
I used mine all winter with plug in tank heater disks laying in the buckets. Can't let buckets go empty though or it can melt nipples.
I LOVE the nipples, but watch the sizes when ordering from ebay, there are chick and adult sizes available.
Also take a look at Colony Raising Rabbits....really interesting, I think I'm going to build a pen for that style this year. I'll put a wire cage bottom tied into the wire wall fencing, so they can't tunnel out, and then put enough dirt so it seems like they can fulfill at least some of their...
Only on the last 2 days to speed it up the fiddly finishing touches before the birds arrived, otherwise it was all me...digging it out in January, starting the build on ice foundation...gonna have to put cement pads under the legs for longer term use...
I started with 15 - 1 year old Rhode...
Love the hutch you built, working on planning mine now and was curious about the cleaning aspect of yours. Does the slant between the levels mean the poop goes down and out between the lower level boxes? What changes would you make if any?
Nicole