RobG7aChattTN

You might want to run the pump all night as well to help to distribute the heat from the water to the air in the greenhouse. The beauty of the system is that it will reduce temperature during the day when most greenhouses get too hot and radiates that stored warmth at night. I tried large 500 gallon tanks of water that were white with no water flow. The water stayed cold and I feel it did little to radiate warmth at night. I'm thinking about painting them black and adding a solar pump to circulate water. Solar would only operate during the day, but my greenhouse is too far from my house to plug a pump in. During the day my greenhouse often gets far too hot and I wish I could capture some of that heat in water. They make some really nice, thin black plastic water tanks for just this purpose but they are very expensive. They don't use a pump, but cover a large area and are relatively thin so the water heats up and releases that heat fairly easily. Anyhow, good luck. It looks like a good system and I hope it works for you.