The Panda Film Black & White Waterproof Film 50' x 150' provides durable light control and moisture protection for large hydroponic growing operations. Constructed from heavy-duty 7 mil polyethylene, this film features a white side that reflects light back toward plants to support even light distribution and a black side that blocks light to help reduce algae growth and prevent light ... https://www.hydroponicstown.com/811755-black-white-film-50-x150-7mil-3-year