All transparent pipe used for photobioreactor or other outdoor applications shall be manufactured from a PolyVinyl Chloride (PVC) compound with a minimum Cell Classification of 11553 per ASTM D1784. This material shall be a UV stabilized PVC material and shall exhibit a slight blue tint. The pipe shall be manufactured to iron pipe size diameters in either ThinWall pipe dimensions that have been optimized for light transmission, or Schedule 40 pipe dimensions as applicable. The pipe shall be manufactured in the USA by an ISO 9001 certified manufacturer. All PVC clear pipe shall be packaged immediately after its manufacture to prevent damage, and shall then be stored indoors at the manufacturing site until shipped from factory. All pipe shall be manufactured by Georg Fischer Harvel LLC, trade name EnviroKing®UV ThinWall™, or EnviroKing®UV Schedule 40 as applicable.