1-Wire : Light/Temp Monitor : for fish tank

Hi, I'm just new in here and since emonTX v3 is available I will start my project.

Monitor My apartment temp/humidity/power and fish tank monitor.

I'd like to monitor/gaph temperature of my fish tank, I will use the Encapsulated DS18B20 temperature sensor. Is this part really waterproof ? I need to monitor the temp of the water !

I'd like also to monitor the presence of light in my tank do you think I can use this 1wire sensor with the emonTX v3 ? Encapsulated DS18B20 temperature sensor : http://www.embeddeddatasystems.com/D2Photo--Low-Cost-1-Wire-Light-Monitor_p_13.html