Greenhouse Microclimates

I just placed metal shelving in my greenhouse at different levels and place plants on shelves according to their need for light. For example, I place Catteleya Orchids on the top shelf because they need direct sunlight. In the winter, I place five 50 gallon water barrels in the greenhouse to keep up the humidity and to heat the greenhouse during the night by releasing the latent heat of water. I also have tropical fish tanks in the greenhouse and use the fish water to water the orchids. Click on this GREENHOUSE LINK TO VIEW MY GREENHOUSE