How to choose coolant for your custom watercooling loop

How to choose coolant for your custom watercooling loop

There are many things to look into and to choose when building a custom loop - various resources, opinions, outdated guides, you get the picture. This is why I have decided to make a concise, easy-to-understand guide about watercooling; from choosing the various parts to actually assembling the loop yourself. 

In today's entry, I'll be talking about how to choose a coolant for your custom loop. There are many types of coolant available on the market, so this can be confusing; many brands offer different solutions. Remember that you can't simply use tap water; the minerals are bad for your loop. Distilled water by itself is also not sufficient; which is why all coolants on the market will contain some kind of biocide or corrosion inhibitor, which is necessary for your loop.

With any type of coolant, I thoroughly recommend you flush your radiators with hot distilled water prior to assembling your loop. Failure to do this may result in serious loop and coolant issues, that mean you may have to disassemble your loop entirely.

The different types of coolant

There are three different types of coolant that are used in a custom loop: clear coolants, dyed coolants and opaque coolants. 

Clear coolant picture

Let's start with the first type, clear coolant. Aesthetically, it looks just like water, it's transparent, as you can see above in a custom loop I recently built with clear coolant. An advantage of using clear coolant is that it requires less maintenance; you only have to change out the coolant every 8-12 months when you use clear.

EK Dyed Coolant

Next, let's move on to dyed coolant. Dyed coolant, as the name suggests, has some colour to it, but remains translucent, as you can see in this image from EK. Dyed coolant requires some more maintenance; you have to usually change out the coolant every 6-8 months. As with all coloured coolants, there is a chance that components in your loop, such as tubing and water blocks, are stained due to this coolant. If you are willing to take your loop apart and clean it if this does happen, that's fine, but bear this factor in mind. Sometimes staining is unavoidable with coloured coolants, but to try and prevent it long-term you could remove the coolant, flush the loop with distilled water for 12-24 hours only, and add a new batch of coolant every few months. 

EK Solid Colour

Lastly, let's cover opaque coolant. As you can see above, opaque coolant, also known as 'solid' cannot be seen through. Many people desire this effect in their loop, however opaque coolants can come with serious consequences. The opaque effect is created by suspending coloured particles in the coolant; these particles can sometimes fall out and get stuck in your radiators or the fins of your water blocks. Not only does this mean that your coolant will no longer be the solid colour you desire it to be, there will be many particles trapped in your blocks and radiators, meaning that you must take apart your loop and clean all of these particles out, even taking apart the individual water blocks and scrubbing out the particles with a toothbrush, or else you'll face sub-par cooling and worse flow rates; maybe even a damaged water block if it isn't taken care of. Showcase coolants such as Primochill Vue or EK Mystic Fog are also included in this category. 

But which should I buy?


After all of that explanation, let's get down to the actual question, which is the 'best'? Which should be bought? Well, each one has its own ideal buyer. 

Clear coolant: someone who wants a coolant that doesn't require much maintenance; that doesn't have to be changed out often. Also someone who wants to keep risk of particle fallout (and loop clogging) as low as possible. 

Dyed coolant: someone who wants some colour in their coolant, but who doesn't want the risks of an opaque coolant. Someone who is willing to perform a little more maintenance, and take their loop apart on the small chance that the particles do fall out. 

Opaque coolant: someone who really wants a spectacular build, who wants to have their loop looking exactly the way they want. Someone who is willing to perform fairly regular maintenance (every 3-4 months) and is willing to take apart all the components in their loop if the particles do fall out. 

I should probably add that I always use clear coolant in all of my builds, because it's simply the easiest and safest. If you want the extra colour, I would go with a dyed coolant. The only real circumstance I would recommend an opaque coolant in is if you are doing a showcase build that is going to be torn down a week or so after assembly. 

Which brands are good?

This is a good question, it often comes down to personal preference, but here are my personal recommendations. 

In my opinion, the best coolant out there is AquaComputer DP Ultra. In addition, Corsair's XL5 and XL8 are good, as well as Koolance 702/705 solutions, and lastly Mayhems X1. 

*I do not work for any of these companies, or sell coolant myself, these are my own views*



I hope this guide on coolants has been helpful; I hope I have helped you clarify some doubts or learn something new about custom watercooling! If you have any questions, please do contact me using the 'contact us' section of our website :)

Happy watercooling!

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