Ok well in spite of me being up all night for work, i plan to build a removable greenhouse for my tort! San Francisco weather is nice but not for the tortoise! I figure why not build a removable green house for the outdoor enclosure. So i did my research and i might as well ask you guys, what is your thought when using polyethylene plastic for the cover?! Do you guys know any type of plastic that dont really block the UV? If so, please let me know as soon as possible. I plan to keep Shelby outside year round now because she is getting way to big and would appreciate a bigger enclosure.