Iron Man has a new project on Kickstarter. I just want to give it a plug here. The AquaPlumb is a liquid level sensor that can have so many applications and can be used with many different types of liquids. Whether you want remote monitoring and replenishing of livestock water tanks, control of aquaponic systems or aquariums, monitoring of flood alarms or even to create an electronic toilet, it's uses are many and varied. Check it out.
Thanks for looking!