Actually the light was so I don't break my neck at night. I use the hoophouse as a hardening house during late-March through Early-May. I used a crystal clear 16-mil greenhouse film on my greenhouse. It has stood up to 60mph winds, golf-ball size hail, and 28" of snow. the material is called Eskay-Lite Greenhouse Film. I can literally stand on the material on the roof.
http://www.hotwiredgardens.com/pdf/G...Heavy_Snow.pdf
I covered a 12'x16' peaked greenhouse with a $121 roll of Film and had quite a bit left. This is the third winter and it still looks like new
http://imageshack.us/a/img602/776/197.jpg .