I don't have one right in front of me to verify, but I believe the lower hole points towards the plastic difuser (there's an internal plastic "shelf"). If that's the case then the lower hole should actually be your return so that the bubbles hit up against it.
__________________ EVGA X58 3X SLI / i7 980X / 3X 4G Mushkin Blackline Frostbite / XFX Pro 1000W / EVGA GTX 680 SC+ 2GB / Corsair F120 / WD 6401AALS / TT Lvl 10 GT Swiftech MCP655 WC Pump / EK XT 240 Rad / 2X Scythe Ultra Kaze / EK Supreme HF / Primochill Myriad Dual Bay Res / Dell UltraSharp U2412M Sabertooth 990FX / PhII X4 965 / 2X4G Corsair XMS3 / EVGA GTX580 + EK Block / Corsair 120G Force GT Corsair TX750 / XSPC EX240 / Swiftech MCP655-B / XSPC Dual Bay Res / ? CPU block / Bitfenix Ghost / Samsung 931BF |