A Thought About Water Cooling

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Good overview of watercooling choices ans information sources – The Rudy

I don’t want anyone who has seen these pictures of my water cooling rig to rush out and get water cooling thinking that they’ll be able to overclock their CPU to the wazoo speed.

Water cooling may NOT improve your overclock.

It can only be as good relative to your ambient temperature.

Overclocking depends on many factors, temperature is not the only one.

If you’re already using the best aircooling system out there, water cooling may or may not improve your temperature very much. However, it definitely WILL improve the noise level. The most efficient air cooling systems currently use very high rpm fans and exhibit loud noises. My watercooling rig uses only 2 120 mm low rpm (2000) low noise (30 dBA) fans.

What I also noticed is the temperature after running full load drops like a rock, much faster than aircooling. And the max temp (load temp) of water cool is sooooo effective.

How Water Cooling Works

Water travels through tubes into the waterblock attached on top of your CPU. This transfers heat from the CPU onto the waterblock and heat is carried by the water out of the water block through the tubes into the reservoir.

The pump then sucks the warm water from the reservoir and sends it to the radiator, which makes contact with the water and dissipates heat. The fins of the radiator are cooled by fans blowing through the fins. This cools the water which then flows from the radiator back into the waterblock, thus completing the cycle.


The most popular water flow arrangement is:


This is so because you have cool water flowing out of the radiator into the water block to cool off the CPU right away. Note, if you choose not to have a reservoir, then replace it with a T-line.

Here’s a picture of the flow:



The Rudy


Here are my thoughts on where you should put your water cooler.

Internal is neat, self contained and even more quiet because once you close it all up in the case, chances are the dampening factor/material of your case, if it has any, may help to drown out any noise generated from the fan(s) which cools the radiator. The disadvantage(s):

  • Space limitation;
  • Must make mods to your case;
  • Greater risk should an accident occur.

With external, you can use as large a radiator as you’d like, or even multiple radiators. Should an accident occur, it minimizes the risk. Should any of the connections leak, the liquid would remain in your external case and not spill over to your system. The only connection at risk here is between the tubes and water block. Enough said?

Case 1


Case 2



If you purchased a water block and it’s not lapped (you can’t see your face in it), the surface of the water block is probably rough and may leave grooves behind that do not allow for good, flat contact with the CPU (it’s microscopic, so you won’t be able to tell by observation). This may result in poor perfomance and heat transfer.

Here’s what you do. Get some sandpaper and a sanding block or just use a flat surface to sand your water block.

Depending on the roughness of your water block, you need to start out using 400 or 600 grade. Sand the block only ONE direction by placing the water block on the sandpaper, brush, then lift it off the paper. Repeat the motion after 15 or 20 minutes to get a smoooooth surface, then move onto the next grade, 1500 or 2000 and repeat the process.

You should see a shine good enough to see yourself in it. Try not to touch the surface with your overly greasy fingers. And don’t forget to use Artic Silver thermal paste.

I’ll leave the installation instruction of the water block to the manufacturer’s installation guide – they all can be different.

The Rudy


OK – so after you’ve purchased all the parts below and have decided where you want to install the system (inside or outside the case in an external rig like mine), you’re ready to hook them all up as diagrammed above.

Remember, the size of the radiator determines where you can install your watercooling system. Be sure that the air blowing from the fan onto the radiator must go somewhere, preferably not back into the case again. You can install a push and pull radiator/fan system if you’d like. This is where the radiator is sandwiched between 2 fans, one blowing and one sucking the air away.

Now, measure your tubes to the correct length and make sure it’s free from kinks, thus it won’t restrict water flow. If you can, I would recommend a barb to everywhere you connect your tube. The barb is designed to attach to a tube and makes it easier to use a hose clamp, preventing leakage. It’s most effective.

To every threaded connection that you have, I recommend you use Teflon tape (listed below) and sealant just to be on the safe side. Try not to use any elbows in your setup if you can – should you have to use one, select one with the widest possible angle.

I recommend using a reservoir. I think it makes your life easier when filling and bleeding the system.

Bleeding is a process to get all bubbles out of the system. Just make sure whether the reservoir is purchased or DIY, that one of the reservoir outlets that goes to the pump inlet is the lower outlet of the reservoir.

This is crucial when it comes to bleeding the system, in that it would allow the pump to suck in nothing but water (no air, no bubbles). Thus this water will help to push all the air through the system and eventually returning into the reservoir at the higher inlet, allowing air bubbles to escape. That means leaving the reservoir opening opened while you’re bleeding the system.

Now mix your coolant according to the manufacturer’s instructions. After you have all tube lengths measured, hook them onto all parts and clamp. Do not attach it inside your case or onto the MB just yet (unlike the picture here). You don’t want it to leak onto your motherboard during testing, do you?

If you can, fill the radiator with the coolant solution first, then clamp it. Now fill the reservoir and hold it up and allow it fill the tube. It won’t fill all the tubes yet, but it will once you turn on the pump.

The solution in the reservoir will start to travel thru the tubes quickly. Just keep filling the reservoir until the system is almost completely full. If you’re using a reservoir, the system will bleed the air for you in a few minutes, then fill up the reservoir to the top and voila, you’re water cooling…well not yet. You want to leak test it for at least 24 hour.

Remember, the goal here is to get all air/bubbles out of the system. Air/bubbles can create noise when it goes through the pump. Bruce Lee once said, “Be water my friend.”

If you decided to use a T-line, You should fill the entire system with water as much as possible before you clamp the tubes – this way would be easier. Then make sure while you’re filling/bleeding the system, that the T-line is at the highest point of the system to help the air leaving the tubes through the T-line.

One suggestion I can make is that if you use a T-line, submerge your system parts in a bucket of water as much as you can, then fill/bleed the rest of your system through your T-line.



The Rudy


After you’ve filled and bled your system, then it’s time to leak test it. If you’re using a colored coolant, it should help you to inspect for leakage. Otherwise I suggest that you use some sort of water dye to give some added appearance, but mostly to aid you in detecting leakage.

If you have clamped your system properly, chances are you won’t see water dripping out like a faucet. It’s the little seeping action that really is the pitfall of a watercooling system. It won’t leak much, but maybe a drop of two in the span of hours – this can accumulates into a puddle of water over time.

I would wrap a plain white paper towel around all joints and let it sit there for at least 12 to 24 hours. Examine the paper towel frequently and it’ll show any leaks and its location, because the color of the coolant will stain the white paper towel.

Casual observation of the joints/connections may not identify any problems. Better yet, let your fingers feel around the tubes and connection to detect moisture. If it’s just seeping through, even with water dye it’s almost invisible to the human eye.

Most of the disasters that I have seen or experienced have been the results of slow seeping action from a connection. I would even leave the case open for a few days while inspecting the system on a regular basis. I can’t stress enough about the patience that you may need to exercise to leak test your system.

That’s it!! find the leakage and fix it with your teflon tape or sealant or just simply tighten it.



What if your pump stops to work? Well by now, I hope that you have a temperature monitoring program to alarm you. Or the BIOS may have a setting that would automatically shut down the system should a certain temperature be reached.

For the most part, you can get all your needs from these places:

Danger Den
Cool Technica


Here are some parts you’ll be familiar with:


A word about barbs: It may sounds strange, but not all barbs are made the same. The one that has the tightest fit is the barb that you want (the one with the bigger head, if you have a choice). The one that just fits perfectly inside your tube is the one that may require you to really tighten the hose clamps – keep a close eye on it during the leak testing phase.

The Rudy


Clear flex 60 or Tygon. Tygon is best but expensive at around $3 a foot. Clear flex 60 is not as good as Tygon but good, much cheaper and you can get it for 65 cents/ft from McMaster or USPlastic.

You want to get 1/2″ ID (inside dimension) with 1/8″ thickness. Thinner walls may allow the tube to kink, thus restricting water flow.

You can get it at…McMaster or USPlastic or any of the sites I listed above. Look for tygon or chemical tubing if you go to McMaster or USPlastic. Get about 10 feet. At McMaster, you won’t see clearflex listed but it’s their chemical tubing at 65 cents. This is same as clearflex 60 – it’s printed on the tube.

I wouldn’t recommend those cheap plastic/vinyl tubes from Home Depot or your local hardware store. They’re hard, won’t bend and more likely to put more pressure on the joints and connections. If they do bend, their radius circle is not much and likely to kink.

Bottom line: You want flexible, thick tubes.

OKAY OKAY – you can do a 3/8″ system if you’d like.


Don’t go cheap on this. The Dtek TC-4 and Danger Den Maze3 is considered best at this moment. Slight edge to Dtek TC-4 from what I’ve heard. Go with a copper top to be safe, it won’t crack like a poly top. The Poly top is a see through top and in the old days they had problems, but now they made it thicker to prevent cracking.

There’s a model about to come out …White Water… that’s supposed to be really good, but it’ll cost you. Or the Maze4 is being tested right now. No test comparisons on these newer models as of yet.

Here’s a picture of a poly top waterblock:



Eheim is best known for its quality. Hydor is also up there but not as well known as the Eheim – but cheaper. There’s also Danner Mag which you can get from Petsmart (lots of people also have used these). Look at their GPH (gallons per hour) ratings. If you should buy one of these models, they should be fine.

How long they’ll last I can’t say. Frankly, if your system does not consist of long tubing, a model like the Danner Mag 2 would do fine. You want high flow rates, but at the same time the pump may also give off more heat, so look at the amperage it uses too.
Note: If you still have air, bubbles in the lines, it may cause noise in your system, but they all are generally quiet.

Costs: Eheim 1250 ($68), Hydor L30 ($50), Danner Mag model 2 and model 3 ($35 to $45).

Also an honorable mention: Via Aqua 1300. Pay some attention to the wattage usage. The more electricity it uses, the more heat it generates and transfers back into your system.

Fittings for the water pump: Some come with fittings (barb, mips etc.), others you may have to purchase yourself. Remember, you’re building a 1/2″ system, so pay attention to the “ID” and “OD” specification. ID is inside dimension and OD is outside dimension.

Here’s a WaterPump Review of some of the mentioned water pumps.

The Rudy

RESERVOIR (optional)

This is optional but I would recommend it. It will make your life sooooo much easier later when you fill/bleed the system. Bleeding is the process of getting air bubbles out of the system. Or, you can use a T-line (cost about a buck at Home Depot). A T-line takes much longer to fill the system and harder to bleed.

The reservoir can be any of the models you’ll find at the www sites I listed above. But try to get one that has a higher/lower intake/outake, as I’ve explained above. Or, you can make your own reservoir. It’s just a container that has inlet and outlet (make sure you use barbs).

If you want to make your own reservoir, GO HERE.

RELAY (optional)

This is to control your pump when you turn on your PC and to make sure that you have water flowing, otherwise your CPU may be fried. Or you can turn the pump on yourself manually before you turn on the computer, but risk forgetting and possibly damaging the CPU.

Prices range from $3 for a DIY Relay to $30 for ready made. The $30 is a PCI card relay and doesn’t require you to drill a hole in your case (DangerDen Relay  
CoolTechnica Relay).


The purpose here is corrosion protection and water temperature cooling. One of the more popular brands is Water Wetter, at around $7.50 for 12 ounces. You’ll probably only need 4 ounces at $3.50. The ratio is supposed to be 4 ounces per gallon.

It is also possible Zerex from Valvoline or (my favorite) – Toyota Red coolant.

Water wetter is popular but it stinks!! It does give off an odor and I threw it away. I like Toyota red coolant because I use it to protect my $35K car, so it must be good for a $200 water pump system, heh? Plus I like that color!!!

Frankly, just use any good reliable coolant that you know. You probably want to change out the fluid every 6 months or a year or so.

One more note: Use distilled water when mixing coolant. YES, distilled water at a buck a gallon from your grocery store. It’ll conduct less electricity if you accidently spill it onto your motherboard or electronic parts. It may save your system, speaking from personal experience 🙂
Unless you can afford to get deionized water, then go for it. It won’t conduct electricity much or any at all, but costly.

By the way, I haven’t heard of any concerns/worries about algae growing inside a car’s radiator 🙂


Find the highest CFM fans and lowest dBA you can find. Supposedly below 30 dBA, it begins to have little or any audible effect to the human ear. Mine is the aluminum Evercool 120 mm at 2000 rpm, 80 CFM at 30 dBA. Remember, rpms are what causes noise and this is common with smaller case fans.

Smaller fans produce much less CFM at higher RPM than larger fans. You need as many fans to accomodate the size of your heater core. Usually you need either 1 or 2 120 mm fans depending on your heatercore’s size. Of course you can use smaller fans too, but why?

The purpose of a shroud is to help eliminate the dead spot from the fan and gather up all the air volume to deliver it to the radiator.
You can purchase premade shrouds from DTEK, Danger Den or make your own. Depending on the size of your radiator, you can purchase a RubberMaid container from the grocery store and cut its bottom out. The bottom has an indent that is just about the size of a 120 mm fan.

A shroud from DTEK:


But make sure it would fit the way you want on your radiator.

If you want to make your own shroud, GO HERE.

The Rudy

RADIATOR (or heatercore)

Well, this is where you can save lots of money by purchasing a car heatercore and use it for the radiator. Or you can get one from DTEK or Danger Den for anywhere from $50 to $100. Mine cost me $18 from Autozone (10 1/2″ X 2″ X 5/34″).

It’s nothing but a car heatercore. Yet the most crucial part, just like the water block. The larger the radiator, the more effective it is. So figure out where you want to store it and size it. If you make an external water case like mine, you have more freedom on the size.

You can go here to this site and find a car radiator at any size you need, then go to the Autozone or Pep Boys and get them for cheap, or even at a car junk yard.

A rule of thumb: An old chevy car radiator is usually cheap. The more popular ones are: Chevy Chevette, Chevy Caprice or Cavalier …all from 1977 to 1988…check the database.

If you come across a radiator with inlet size 3/4″ or 5/8 and you’re building a 1/2″ system, don’t worry. Usually the 3/4″ can be cut down to where it’s actually 5/8″. Frankly, 5/8″ is best because you can fit your 1/2″ tubing over 5/8″ by heating it up in boiling water for a minute or two. It’ll seal tight once it’s cold and won’t leak – but use clamps anyway.

Go here to find your radiator core sizes and here to cross reference for model numbers.

Notice that you can search at NapaOnline or AutoZone by part numbers.

If you don’t want to DIY and purchase something all set up for you, DTEK and CoolTechnica have a combo for around $55. You can get one or two depending on the level of performance you want.

If you decide to paint your radiator, only make a thin coat. Too thick a coating will turn your radiator into an insulator, thus inhibiting heat transfer and thus decreasing the performance as a result.
You can put more paint on the outside of the radiator (the side and tubes) but don’t put too much paint on the fin system.

A good suggestion is the “Plastikote” that I found at Pep Boys. It goes on as a thin coat and dries fast.


Clamps!! Go to Home Depot’s plumbing department and look for those metal clamps with screws. I like these much better because they’re what plumbers use. They cost around 80 cents each – get one for each connections.

Teflon sealant tape. Yes, from the plumbing department too. Wrap it around any threads you may have to help prevent leakage. Wrap it clockwise because it’s the same direction you tighten your barb or mips or whatever :). If you wrap it the wrong direction, you’ll know because it will come loose when you begin to screw it into place. Wrap it maybe a couple of

I would consider putting some sealant/Form-a-gasket on the outside joint of the water block where the fitting is connected. You don’t want water to seep through here and onto your CPU. Just a good precaution. Permatex is a brand that has lots of sealant and Form-a-gasket product.

Be careful as to which you use – some are permanent adhesive and some are not, so this is dependent on where you use your parts and the intentions of the usage
(Teflon Tape here.)

Or use all of the above at all your connections 🙂 You can’t be too safe.

Here’s a Goo Guide that I found online that could be helpful.

Sound dampening foam. You can get this at an auto parts store. Place it underneath the pump and it’ll help to dampen the low vibration noise that the pump may exhibit. Or use some foam pads, rubber tube pieces cut in half or even just a piece of cloth. It’s to dampen a low humming vibration, that’s all.

The Rudy


Water Dye with UV? don’t ya’ want them glowing in UV lights?? hehehe….


Some people use a product called Ritz from the local grocery stores. It’s Whitener & Brightener fabric application and acts as a UV solution. But you can also get other Ritz dye for different colors. Be careful when using the Whiter & Brightner – it may create lots of foam and bubbles; after all, it’s a sort of a detergent.

Or you can go to Pep Boys and look for automotive leak testing UV dye fluid. It’s around 5 bucks. Mechanics use it to look for leakage. It comes in a couple of small greenish/yellowish containers. I believe there’s a version for oil and another version for coolant/fluid.

Thanks to all whose pictures & references I have used. This guide is meant to help out those who are new to water cooling. And thanks to JoeC and Newbie_Doo for posting this for all to see.

Just DO IT!!!   IT’S FUN!!  🙂

The Rudy


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