A quick post to provide a link to the latest available code :
This link contains the code that runs on the raspberry pi. However, this is mostly just python code, and the essential aquarium functions use nothing specific to the pi. The only specific files that are written for the raspi are the ones that prints stuff onto a 20*4 lcd screen. the rest is compatible with any linux box.
The www folder contains php files to provide a simple way to control it over the network (be warned, it's extremely basic code, and it will really need to be fleshed out in order to obtain a nice interface, as of now it's just a way to call the python scripts through an URL via a browser).
The arduino folder contains rlieh3.ino, the code that has to be uploaded onto a whateverduino (arduino uno, leonardo, mega, etc... basically anything with a Atmega 328p, a 32u4 or anything bigger).
Once hooked with sensors and stuff, it will be able to control various organs. I'll soon put instructions for hooking up. As of now, some instructions can be found on the old fritzing sketches, and pins must be figured by reading the top of the code (everything is specified there, with comments), or even changed in the code.