Alright...well, I put the circuit together and it seemed to work when testing with a LED. The LED was off, then when I dipped the probes in water it was nice and bright. Well, I bought a buzzer, and it buzzes when the probes are out of water. I tested with the LED again and it worked fine. Come to find out, it is giving 0.523v when the probes are out of water! How can I fix this? I've tried swapping out the resistor all the way up to 10meg ohms and all the way down to 1 ohm with no luck. Am I missing something here?