Rocket stove heat for winter plant growth

In preparation for next winter, we are trying to put heat into one of our greens hoophouses. This would allow us to grow tomatoes and cucumbers out of season, as well as give our fig trees a fighting chance!

To accomplish this, we are trying to build a rocket stove, a super-efficient wood-burning stove that uses the ground below the hoophouse as a heat battery. We are also going to use the thermal mass of water to store heat and either act as part of a hot tub system or a winter aquaponics setup.