The waterblock feels smooth to the touch, and the machining on the bottom is quite visible. There were however a few scratches (which I attribute to the fact that this model was not exactly brand new (I believe another site had used this unit for reviewing purposes.) Regardless, the scratches didn't seem to be in the center of the block, so testing both P4 and K7 CPUs shouldn't be effected by it.

All right, now on to the fun stuff. To crack open the system, all that was needed was a screwdriver and a bit of force (the screws are screwed in perpendicular to the faceplate from the sides.)

Here we can see the Hydrocool's radiator, as well as the connectors for the hoses and the PC connector. There is only one fan in the Hydrocool unit, and it is mounted to the radiator, thereby reducing the total amount of noise that the Hydrocool can possibly create.

I have documented the water flow as follows:

The reservoir sits connected to the inlet pipe of the pump.

From there the water flows up, through the water flow meter (which is lighted so that the user can verify water flow.)

The water takes a 90° turn.

And goes into the radiator, which is actively cooled by the fan.

Then the water is routed back through the enclosure (lower tubing) under the water flow meter.

Under the pump.

And out to the waterblock.

Once the water goes through the water block, it comes back to the lower port and is replaced into the reservoir.

A basic outline of the system is as follows: Reservoir --> Pump --> Water Flow Meter --> Radiator --> Water Block --> Reservoir

There have been many debates as to the "proper" location of a radiator - some argue that the radiator should be right before the water block to cool the water down before it hits the CPU. Others believe that it should be right before the reservoir. Either way works, however, and if you are concerned that the Hydrocool's reservoir water is going to be to hot, at least be assured that the coldest water in the reservoir is being drawn, seeing as the pump inlet is located at the bottom of the reservoir (heat rises.)

I also want to point out just how big the radiator fan is in the Hydrocool. I measured it in at 5 inches, and the radiator is the same size.

The reservoir has two openings - one is positioned slightly below the other. The leftmost opening is plugged with a yellow cap and has two wires coming out of it. This is the fill meter, which monitors how much water is present in the reservoir - if there isn't enough liquid for the unit to properly function, the "FILL" alarm will go off (a repetitive beeping, and the word "FILL" on the LCD,) until the unit is satisfied that there is enough water in the reservoir. The other hole is plugged by a screw in cap and is the location for putting the distilled water and additive mixture into the unit.

The reservoir measures at about 4.5" high, and is a little more than ¾ of the unit's width.

I found the thermal paste to be quite difficult to work with. It was much more viscous than Arctic Silver as well as the generic paste you find in a blister pack; it was very hard to spread, and would bunch up often. Just a warning here, after testing the Hydrocool on my P4, I went to take the Hydrocool out of the system so that I could get my K7 temps. I lightly tugged on the waterblock after removing the retention mechanism, and the waterblock stuck to the CPU. I pulled a little harder and the waterblock came off.

Or so I thought. Unfortunately my CPU came out with the waterblock (thereby irrevocably damaging one of the pins.) I had to move the CPU around on the block just to get it off. Whether this be caused by the block, the paste, or even the motherboard, I have no way of testing this again as I have run out of Corsair's thermal paste. The stock HSF and the Aero4 I tested did not have this problem with Arctic Silver.

The hose connectors are something to take note of. Both the "port" on the Hydrocool and the connectors have two-way seals, and once a hose is disconnected from the unit, a small amount of water will come out (the water that was present in the connector before the seal.) The end of the connector has a ring that is depressed when the connector is attached to its port, which allows water to flow either way through the connector.

The rear of the Hydrocool has the complementary power and data port, as well as 2 "ports" which offer quick-release buttons (the metal that is connected to the plastic ports.) By pushing the connector into the port, a small metal button is pushed and the quick release button springs out. To release the connector, you only need to push the quick release button and the connector pops out of the port.

The additive is included with the Hydrocool so that there isn't any rust formed due to a metal interaction (I believe between the pump, radiator, and waterblock,) and also serves as a means to kill off any possible bacteria growth.

The last thing you want is algae clogging up your watercooling system and hurting performance. The instructions say the additive is "pet safe" although if it's ingested it is supposed to be harmful… I'm not sure exactly how those two statements don't contradict each other - just don't drink the stuff.

Installation

Installation was quite honestly a breeze.

First the retention clip must be routed through the hosing, and then the hoses must be routed through the PCI slot. Finally put the black hose shrouds over the lines.

The hoses need to go through the P4 shrouds' opening.

Then attach the hose adapters, they fit snugly with the tubing, and the plastic hose clamps are a cinch to click closed. However, the 90° adapters will not fit through a PCI slot. If for whatever reason the hoses need to come back through the PCI slots (if you need to put a different clip on the water block, or want to change systems.) To get the hosing back through the PCI slots the 90 degree connectors must be cut off from the tubing, and then re-inserted into the tubing once it has been re-routed.

Hook up your power switch connector to the Hydrocool's power connector, plug the water block's thermal probe into the PC interface card, and plug the molex connector into the interface card.

Apply the thermal compound to the CPU...

...attach the water block.

Mix distilled water with the additive.

You can find distilled water at Walmart, Wallgreens, CVS, or at a supermarket.