Swiftech H20-220 Apex Ultra Watercooling Kit
 

Finally, I got to the point where the system was pretty much solid with
opaque, light green liquid, which had lots and lots of air bubbles in
suspension. This isn't great, but with a properly setup circuit
(reservoir being at the top, remember?), all the air will filter to the
top of the reservoir and the coolant in the circuit will slowly be
purged of bubbles. You might want to tap and rotate the various
components while the pump is running, so that bubbles will dislodge and
be carried to the reservoir by the coolant.