Building this greenhouse was quite a project.  It started when our neighbor to the East volunteered to donate some trusses and some plate glass doors. He was a building inspector and managed to collect defective building material. The sliding glass doors were 3 x 8 foot and some 4 x 8 foot. Constructed as two pieces of glass separated by about ¼ inch air space. I was able to separate the glass panels which were about 3/16 inches thick plate glass. I installed single panes for the walls and roof. Two sets of 4 x 8 sliding doors (front and back) using the double pane glass.

I used a plastic watering tank for use as a goldfish pond. Circulated water using an aquatic water pump. The water was pumped up about 7 feet above the pond then drained sequentially into 4 water trays back to the pond. The process allowed oxygen to be added to the water as it flowed continuously.  There was a float valve in the tank that controlled the water level.

I installed an automatic sprinkler system to maintain humidity, then abandoned that for a small evaporative cooling unit. The gables had automatic vents that closed at night when it got cooler and opened again when it warmed up during the day.