We put up a small greenhouse on part of our patio each winter to keep some tropicals warm and toasty. It's about 24 ft across the back. The gutter drains into a 300 gallon rain tank at the end of the patio.
The PVC pipe is laid out at 4 ft intervals
Plastic is attached to a board under the eaves.
The PVC pipe is screwed into the board under the eaves. The other end of the pipe is threaded onto rebar at the end of the patio.
After all the pots get in, we close the end up with plastic and a door.
Ready for winter