Is it a CPR Bakpak 2?
If it's a bakpak, just hang it on the back of the tank, pop on the powerhead in the inlet in front of the tank (in the water), and turn on the power.
If it's not a bakpak you're talking about, I have no idea.
Coralwish,
If you go to the companies website(CPRUSA.COM) they have instructions there that you can follow. They also have message boards to assist you with any problems.