I worked hard this Labor Day weekend to get my aquarium controlling nodebot up and running, and I can safely say success! I'll have a series of posts coming up that detail how it works, but the short of it is that I am using a Raspberry Pi running Node.js connected to the lighting system in my aquarium that allows for more complex control than simply flicking a manual switch.
The system is configured by a web page hosted on the Raspberry Pi itself. The system can run in one of two modes: automatic or manual. In manual mode, you can directly tell the daytime or nighttime lights to turn on, or to turn off both. In automatic mode, the Raspberry Pi will connect to the internet to determine when sunrise and sunset is for the given day and turn the lights on and off automatically based on this information.
Right now it's just running in manual mode though because I have a timezone related bug in my software right now. It should be fixed in the next few days. In the meantime, check out this video of me controlling my aquarium from my cell phone!
UPDATE: I have a few other posts that talk about the setup in more depth:
Anatomy of a nodebot powered aquarium part 1: overview
Anatomy of a nodebot powered aquarium part 2: the hardware
Anatomy of a nodebot powered aquarium part 3: the software