Use this in mini greenhouse for "rotation planting transplants"? The thermal "battery" in a passive solar greenhouse - barrels of plain old water on the north wall of the structure. Warmed by day, they release their heat at night. Greenhouse Farming, Underground Greenhouse, Greenhouse Plans, Greenhouse Wedding, Indoor Greenhouse, Aquaponics System, Hydroponics, Backyard Aquaponics, Aquaponics Plants