The link below is a tutorial on how to make your own watering sensor. Basically the led lights up when your soil is dry, and when you water it it turns off. http://nurne.blogspot.com/2008/01/water-me-man.html Using this instead of poking your finger into the soil can save you a little bit of time. *edit* How to build your own ppm tester: http://blog.makezine.com/archive/2008/02/build_your_own_water_qual.html *edit, just buy one.* I'll be updating my grow log this weekend as well.
Haha seems awesome. The fact that the kid made amazing schematics for that brings me back to those physics days of drawing those models and shit. That seems like a very promising invention only because the person that made it actually used his head!