Why would you want to water cool a PC? First of all it can much more quiet and it drops the temperature of your computer greatly. My quad core went from 50C under load to 28C Idle and under load! It is also good for overclocking. When you overclock the components of a PC get hot. The more you do it the hotter they get. It gets to a point were air cooling just won't cut it.
I really enjoy water cooling and it recently became one of my new hobbies. A water cooling rig requires maintenance. You need to know your way around a computer pretty well to be able to do this. I've been building computer since I was 10 and this really pushes you to the limit. I want to go even farther and try vapor phase change cooling. It's pretty much building a refrigerator inside of your computer. Drops things to around -20C
The image shows my build before I cleaned up the wiring.
Some more pics of my computer here
Step 1: Finding Your Way Around.
First know your way around a computer. Refer to the pictures.
Step 2: Picking Out the Parts.
Deciding on the parts depends on how much you want to spend. I spent about $275 on my current setup. Its going to be about $375 once I watercool my GPU. A good kit I would recommend is this oneone from petra's tech shop for $250. It has pretty much every single part my kit has. I didn't even know there was this kit before I bought from them. The people there are really nice. ThisThis kit is better for a cheaper build or a smaller system that doesn't throw off as much heat. These kits aren't like ones you will see on newegg or other computer stores. They have a good combination of parts from different company's. The best watercooling rig has parts for all different companies.
You will also need about 10-15 gallons of distilled water. You can pick this up at your local grocery store. You also need tubing. You need to buy the right size tubing according to the type of pump, radiator, waterblock, and reservoir have. They are called barbs. I prefer 1/2 barbs. Make sure all your barbs are the same size. I recommend you use Tygon tubing. You can also use deionized water. I finally figured out the differences, I was pretty confused. Deionized water is less pure then distilled and still has some minerals and things like that in it. Both are still a bit conductive.
You also need some thermal paste. It helps create a strong bond between the CPU and water block so the heat can transfer. You can get a tube of it for about $5
Some places to buy watercooling parts
Petra's Tech Shop (My favorite)
Step 3: Preparing to Install.
Once you get all your parts I would read through all the manuals. I never read manuals, but for watercooling I would. They have warnings that could really mess up your rig if you didn't pay attention to that. After you do that you need to do what is called flushing. When the parts are manufactured they have oils and grime and other things from them being made. If you just run your rig like that you will have dirt and grime flowing through all your parts and it will start to clog. Get some of your tubing cut it short and hook it up to one end of your radiator. Get a funnel and run about a gallon of distilled water through it. It helps to shake it up and around the radiator. Also heating the water helps it too. Next take apart your water block which should be pretty simple just unscrew a few screws. Get some rubbing alcohol and rub it through all the groves in your block.
Step 4: Installing
Take out all the parts of your computer you won't be using. Such as your ram HDD's and GPU if you aren't water cooling it. Your going to need to pretty much have to take apart your computer anyways to install the water block.
Take the motherboard out of your case and put it in a safe place to work on it where static won't get to it. Put a dot sized dab of the thermal paste I mentioned before only a dot or 2. Get your screws that came with the waterblock and stick them up through the bottom of where your heatsink would screw in. Put the heatsink on and secure it.
It is hard to explain since all blocks mount a bit different. Your block should come with some kind of diagram. Think through where you are going to be installing you radiator and water pump. You might have to drill some holes into your case if you are mounting your radiator outside of your case. Once you found the places mount and screw them into place. Put your computer back together with only the essentials as you won't be needing to be able to boot just turn it on.
Plan out how you are going to do the tubing and connect them all on the valves. Get some hoseclamps and tightly secure them on. You might need to use kind of lubricant to get them to slide on. Make sure have things how you want them because it is extremely hard to get the hoses back off.
Step 5: Leak Testing.
This step is crucial because if you have everything in your rig and it does happen to have a major leak it could ruining your computer. This is why you took out everything you don't need. Stuff your case with paper towels and power it on. Watch it for about 10 minutes and go do something for 30 minutes or an hour. Check on it everyonce and a while. You should leave it on for 12-24 hours. 12 is fine but more if you are really concerned. You leave it on so long because small leaks may take time to emerge. The paper towels can also help you find where the leak is. If everything is good and your computer didn't short itself out your good!
Another thing of I just thought of for leak testing is that if your pump doesn't use your PSU for power and the wall you can just plug that in. Another thing you can do is get an extra PSU and just hook the pump up to that. Then you can jump start it. Find a green and black wire on the Motherboard power connector and get a paper clip and bridge the connections. Make sure your PSU isn't plugged in when you do this.
Step 6: Putting Everthing Back In.
Put all the things you took out and put them back in. If you did everything right your computer should turn on and be fine. Monitor temperatures for a bit to see if everything is going right.
Hope this guide helped you and got you into the fun hobby of watercooling!
If you have any problems with building or watercooling feel free to contact me through instructables, IM, or email. Just don't bug me with virus and software questions. If you see something I missed please do tell me I made this thing at 3 am.
Also a great community to participate in is Xtremesystems. They are very helpful and just a great group of people.
Step 7: Additives
There are quite a few things you can add to your loop.
A few I recommend are:
PT nuke - It kills all kinds of bacteria and helps keep your loop from becoming dirty as fast.
Anti Freeze - There seems to be a big debate about this going on in the comment section. I use it and it does seem to help. I mix it in a 1:9 ratio to your water.
Liquid Coolants- There are a whole bunch of these, these are most of the time full water replacements. I have not had any experience with these, but I have mostly heard good things about them. Frozen Cpu stocks a whole bunch of different kinds.
Things to STAY away from:
UV dyes - Not all are bad, but some after a while will soon break down and become thick and murky and can damage pumps and reduce water flow. Make sure to look around and see if any of the reviewers of the product have been using it for a couple months before you buy it.
Step 8: Some Extra Tips.
If your wiring is a mess you can drill some holes where you motherboard rests and feed the cables behind where you motherboard sits and stick them through the hole. It really makes things look a whole lot better.
Get all the bubbles out of your reservoir. It increasing water flow.
Check your water frequently, It might start to grow some things in it or get some dirt in it if you didn't get all the crap out of it when you flushed out the parts.
Put some anti freeze in your water. Put a little in it helps with the heat transfer.
Never use Aluminum and copper or any other different kind of material on the water blocks. It can cause bad reactions. There are some chemicals you can add to protect them but I still don't recommend it.
Keep some extra tubing and distilled water around. If you don't have you reservoir sealed right or just from time the water will evaporate.
If you use black tubing it keeps things from growing in your loop.
KEEP EVERYTHING. Keep all the extra screws you have an old parts. Stuff like that. I don't know how many times all my old stuff I kept has helped me out.