you could add some fish to your water reclamation tank for a small aquaponics system. Grow a few plants to feed the fish and this forms a closed system. There is no need to fertilize, the fish do it for you! Permaculture at its finest!
21 DIY Greenhouses with Great Tutorials: Ultimate collection of THE BEST tutorials on how to build amazing DIY greenhouses, hoop tunnels and cold frames! Lots of inspirations to get you started! - A Piece of Rainbow (outdoor flower planters)
Shed Plans - tile greenhouse floor. I could install something like this over the existing floor and make it easier to sweep. - Now You Can Build ANY Shed In A Weekend Even If You've Zero Woodworking Experience!