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!
DIY Hydroponic Garden Tower - The ULTIMATE hydroponic system growing over 100 plants in 10 sq feet - This DIY Hydroponic Garden Tower grows over 100 plants in less than 10 square feet, by taking advantage of vertical growth space.
Mini Arduino Environment Monitor ** UPDATE - Added RTC ***
This is an Example of how you can use the Arduino to monitor various environmental parameters And display them on a LCD screen. Note: I Added a Real Time Clock! To see the steps, added parts and Sketch I added new steps.