What parts go inside a custom loop?

Posted by Sudsterr Technology on

So you've decided that you want to go for a custom looped PC and now you have a million confusing questions in your mind!

  1. What is a custom loop?
  2. Do I go soft tube or hard tube ?
  3. Do I get compression fittings or soft tube fittings?
  4. What tools do I get
  5. What is a coolant?
  6. What is a reservoir?
  7. What is a radiator?
  8. What is a Pump?
  9. What else do I need ? 
  10. Other Fittings

Decisions decisions decisions!

Don't worry! You're in the right place. We'll take you through all these things step by step and build your custom loop for you!

What is a custom Loop?

If you'd like to know what we're going to talk about in this article, please read the previous article which is an introduction to custom loops. Click here for that article.

Soft Tubing vs Hard Tubing

Hard tubing vs soft tubing

On the left is soft tubing and on the right is hard tubing.

It all comes down to how you want your custom loop to look. If you want your pipes to flex around and look a little more fluid, you could go for for soft tubing.

If you would like to put a little more style and fines into your computer and are ready to put in some effort to bend your hard tubes, then you'll get some fantastic results with hard tubes.

Both soft and hard tubes come in a variety of materials from various manufacturers like ekwb, Bykski, Barrow and more.

They are available in both transparent and solid colours.

Choosing tubing will not result in performance improvement. It is a matter of personal choice.

Tube Fittings

To attach the tubing to the motherboard and radiators, the two popular types of fittings are compression fittings(or simply hard tube fittings) and simply soft tube fittings.

Here are some images. Rigid tubing fitting image and soft tubing fitting image.

Hard tube compression fittings

Soft tube fitting

What tools do I need?

Now to get to the fun bits! You would need the following

  • A measuring tape to measure pipe lengths
  • A pipe cutter for soft tubes or hard tubes
  • A heat gun to bend hard tubes
  • A bending kit to achieve accurate angles
  • Tube inserts - Very important for hard tubing
  • A chamfer tool if required
  • Some patience :) 

 Measuring tapeCustom loop tube cutterCustom loop angle bendersSilicone tube inserts to avoid over bending during heat

What is a coolant?

A coolant or liquid or water(not tap water) is what passes through all your components and the pipes that transfers the heat from one place to another. Coolants are available from various brands and come in various colours and types.

The two main types of coolants are

  1. Concentrate or dye - this is used to add colours to colourless liquid
  2. Pre-mix coolant
ekwb Concentrate redPremix coolants


What is a reservoir?

As you build your custom loop, you need a primary source of liquid that will be passed on to all the parts of your custom loop machine. This can be called a reservoir or a tank. 

Custom loop reservoirs are fun. They come in various shapes and sizes. They even come customised to specific computer cases that will attach itself nicely to the case (but more on that later).

Reservoirs come in various form factors but they can be simply categorized into two types

  1. Reservoirs
  2. Distribution plates or distro plate

Cylindrical reservoirs are simple cylindrical structures that come various heights depending on your requirements. They come with or without pump combined in them. They have inlet, outlet and drain ports. These can be used to transfer water throughout your machine. They can be attached to the side of your case or to the fans on your radiator.

Distribution plates on the other hand are a little more fancy. They are different for each computer case and they have various ports for all parts of your computer and they take up very less space in your computer allowing for large graphics cards and other components.

Cylindrical pump res comboEK Quantum reflection distro plate
Whichever one you choose, we recommend taking the products which have a pump built in the product. You will see these as pumpres combo.

What is a Radiator?

A radiator is the part of your custom loop that will remove the heat from the coolant and send it back to the reservoir. The radiator like any car radiator will have fins to dissipate heat using the air pressure coming from the fans attached to the radiator. The radiator has pipes running through it that will be in turn connected to the reservoir using the fittings that we discussed earlier in this article.

Radiators come in different sizes and shapes. The most common ones are :

  1. 120mm Radiator
  2. 140mm Radiator
  3. 240mm Radiator (Popular)
  4. 280mm Radiator
  5. 360mm Radiator (Popular)
  6. 480mm Radiator

Now all these radiators come in different thicknesses ranging from 24mm and all the way up to 60mm. Most computer cases will not fit very thick radiators therefore, it's better to go for a thickness around 30-40mm.

Radiators for custom loop water cooling

Now, once you've chosen your radiator size, you need to select the fans to go on top of it. Radiators and fans come in white and black. Fans especially are made by almost every computer manufacturer. Some popular companies are Thermaltake, Deepcool, Lian Li, Corsair, Inwin, MSI, Coolermaster, Antec etc.

What is a Pump?

Alright! You've gotten this far! Just a little more to go.

A pump is a device using in machines to push liquid from point A to point B in very simple terms. In our instance, it is what is responsible to push the water/coolant throughout your PC to keep all your parts cool. So this mean that the water only stays in your reservoir/tank if there is no pump pushing liquid from the reservoir into the pipes and radiator and back again. There are two types of pumps - D5 and DDC pumps. We highly recommend just getting a pump + reservoir combo from well known brands to avoid installing pumps separately and to avoid the confusion of whether to go for D5 or DDC.

EK D5 Pump

What else do I need?

You've got the basics. Now to go some important components you need. You need to decide if you want to cool just your CPU or your GPU or both. You can also cool other pieces like your SSD, RAM and Motherboard. Based on this, you need to purchase one or all of the following

  1. CPU Water block
  2. GPU water block
  3. SSD water block
  4. RAM water block
  5. Water cooled motherboard (this is the most expensive)

Once you've decided, we can move on to fittings.

EK CPU Water blockek GPU water block

Other fittings

Last piece of your selections.

Gather all of your components. Count the number of inlets and outlets. Now you need the following

  1. For all the inlets and outlets - you need that many compression fittings or soft tubing fittings
  2. For all ports you don't use - You need rubber sealed plugs so that you don't have a leak
  3. For the places that are suitable for 90 degree or 45 degree bends, just get a 90 or 45 degree fitting rather than bending your tube. You even get 180 degree fittings.
  4. It is recommended to get many more fittings than you might estimate at the beginning because there will always be gotchas as your progress through your build
  5. Find the lowest point in your loop and put a drain valve there. These are going to make your life much easier. Will save you a lot of grief when you want to flush out your loop or clean up something.
  6. Some paper towels to avoid any parts being damaged
  7. Do not power up your motherboard directly. Use a jump starter to test your custom loop without giving power to your components. This will ensure there are no leaks
  8. And finally, you can get a leak testing kit if necessary.


Cool temperatures, stable performance, aesthetically pleasing and top quality parts! Now more than ever, we all want these for our gaming PCs and Workstation PCs. We at Sudsterr Technology are here to make the process as easy as possible.

If you’re ready to buy a custom loop PC, chat with us by clicking the chat icon below to have a no obligation discussion with us or just give us a call on +61470124753 and we can give you a free quote.

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