I tried building one a while back that was much more extensive, it worked well enough for a plant to grow from seed to 2 ft or so, but the light schedule never switched like i wanted it to, i think i was querying my co2 sensor way to fast, and i never finished the grow. this is my attempt to scale back so i can add more features later. the only thing I don't really understand well in this one is the dht11. however i will have a seperate temp gauge to monitor that the fan is keeping temps down.