Here's my 4th and most recent build. I designed this one to be modular. It is currently setup as four 5ftx3ft compartments but can be reconfigured to multiple sized compartments which include 6ft x 10ft, 3ft x 10ft, 5ft x 3ft, and 2.5ft x 3ft...
Just about finished my 3rd cage. It's a 5ft x 2ft with a roll out egg trough. Here's the link... https://www.backyardchickens.com/threads/diy-quail-cage-3-0.1239392/
I think people that had heated buckets with vertical nipples had problems with the nipples themselves freezing up. Nice to know the horizontal do not. I'm installing some tomorrow in my new cage...
Here's a link to the second cage I built with a bunch more pictures. I incorporated more automatic systems in this design including a roll out egg trough, unlimited water supply, and large capacity (ZERO WASTE) feeders. I really like this one...