I think it's all written in the
shop description and the
manual of the poweramp.
You integrate the extra pump into your watercooling loop and place it somewhere in your case. Then you connect the power connector from the pump to the poweramp output and the poweramp input to the 3 pin molex fan connector of the aquaduct card. In the end you have to connect a 4 pin molex power connector from the PSU to the poweramp.
Now you can control the extra pump like a fan.