Once you wired the pump relay up, you can connect a flowswitch (thread somewhere on this forum) between the green line of your mobo connector. If I'm correct this is the on/off line for the PSU... breaking the connection of this line would switch off the PSU, but I may be wrong here... (anyone out there know for sure?)
The idea is that if the pump fails, the flowswitch goes off and tells the PSU to shut down rightaway. Nice, but best not be de-fragging your HD at the time....
