Sun-Lite Storage Tubes can help prevent your greenhouse from going to both high and low temperature extremes at a low cost. Sun-Lite Storage Tubes come in a number of sizes and heights so they can be effectively placed in all styles and shapes of greenhouses. Most lean-to and simple free standing greenhouses are frame structures with very little thermal mass which could mean temperature instability. But, during Fall, Winter, and Spring the mass of these water tubes moderates sunny day interior temperatures to help prevent overheating and retain that heat gained to help keep the greenhouse at a safe growing temperature all night long. The clear water in the tubes will absorb about 50% of the heat energy striking them. The tubes come in 4 standard sizes, 12” x 4’ (22 gallons), 12” x 8’ (45 gals), 18” x 5’ (64 gals), and 18” x 10’(128 gals). The tubes are sealed on the bottom and open on top. (Optional friction fit caps are available for the tops). The sidewalls are .040” Sun-Lite for the 12” diameter tubes and .060” for the 18” diameter tubes. To absorb more heat or to create different decorative effects the water can be “colored” with dyes available in blue, brown, or black. For more information call 603.668.8186 or www.solar-components.com/tubes.htm