Working on my AP greenhouse, just thought I would post some construction pics. Got most of the basic framing up, insulating the floor and filling with gravel. Got a duckweed pool going and a lot of work to go, but I was wondering about heat, both solar and additional heat for those cold days. Is anybody using a Rocket mass heater with water storage in their greenhouse? I was thinking about combining two 330 gallon totes for storage, and pumping it thru Pex in the gravel to deliver the heat. The rocket would heat the air quick and the water would keep the greenhouse warm long after. Any ideas or comments?