Here's the thing about water cooling. We really aren't getting rid of the heat with the water, at least not directly. Air is all we can use to get rid of the heat, because we have so much air, that we can pump the heat out into the room and it'll fly around somwhere else and cool off gradually. The reason why watercooling is so good is because a radiator is like a GIGANTIC heatsink. It allows us to boost the surface area of what we're cooling to a HUGE degree, and then cool it off with a massive heatsink-like object. If you just tried to use a standard heatsink, it wouldn't work. The reason why is that that heatsink would have to deal with the heat of the cpu AND the two peltiers. If it could do that, it would make more sense just to slap that heatsink/dual peltier combo directly on the cpu where it could be efficient.