Why you should change the coolant in your water cooling system regularly

Kevin Hofer

8.8.2019

Translation: machine translated

A water-cooled PC needs regular servicing. Otherwise all sorts of things build up in the loop. I recently realised this with our defective gaming PC.

Yuck. The GPU block of the 1080 Ti is riddled with limescale. The water additive should prevent exactly that. As I want to find out why our gaming PC is no longer running anyway, I take a closer look at the block.

The PC in question is this one, which was assembled by colleagues Christian Seeholzer and Quentin Aellen.

Deposits everywhere

While I'm draining the loop, I realise that the block looks almost worse when it's half empty. What I also notice: The pipes have discoloured and deposits have also formed in certain places.

After removing the graphics card, I can see the full extent: there is residue everywhere. There is also rubbish stuck in the fins. The fins are supposed to improve heat dissipation. If they are clogged, the dissipation no longer works optimally. This could be one reason for the high temperatures that colleague Philipp Rüegg had to contend with during his digitec plays streams.

I open the GPU block to clean it. Most of the debris is between the acrylic glass cover and the cooling block itself. The acrylic has also discoloured due to the colour of the water additive. Let's see if I can get it clean again.

I clean between the slats with a Japanese knife. This is what it looks like after just one pass through the gap:

It's incredible what has accumulated in just over a year. This shows how important it is to regularly maintain a water cooling loop. I clean the GPU block with an all-purpose cloth and some methylated spirits. At the end, I wipe it with a damp cloth.

I can't get everything off, neither on the acrylic plate nor on the GPU block itself. But I'm still happy with the result. After all, the part is no longer brand new, it can look a bit used.

What does the CPU block look like?

The processor in particular got very hot during Phil's streams. I want to know how much debris has built up in the CPU block and open it up. Okay, luckily the CPU block has a milky acrylic top. Otherwise the deposits would be constantly visible. I shudder at what has built up on the block itself.

This looks a lot wilder than on the GPU block. And the slats are much closer together on the CPU block. This will be difficult to clean. I initially proceed in the same way as with the GPU block. After I've removed the roughest parts, I take a fine brush and soak it in methylated spirits. This is how I clean between the fins. A lot still comes out of the narrow channels.

I can't quite get the acrylic top clean. It is glued in one place and therefore cannot be cleaned on the inside.

Regular care is important

I want to know whether other people also have problems with deposits and come across a video by der8auer. He and his partner have even more severe deposits than our gaming PC. This may be due to the fact that our colleagues Chris and Quentin tested a prototype water additive from Alphacool on our PC at the time. It was supposed to prevent deposits. It didn't work quite as well, but at least it wasn't quite as bad for us as in the video.

According to Alphacool, the deposits are colour pigments. The manufacturer advises against the use of food colouring, as used by der8auer. This is because this colour is sugar-based. Permanent heating can cause it to caramelise and harden when switched off. This creates deposits which, according to the manufacturer, can even break pumps.

Alphacool says it therefore relies on detergent chemicals and textile dyes from professional suppliers. These are based on colour pigments in the nano range. However, the manufacturer admits that even these are not designed for continuous operation and that deposits can form.

One thing is clear: there is no cure-all for deposits. Even modern water additives cannot prevent impurities in your water cooling loop. You have no choice but to empty, clean and refill it regularly. And even so, the fact remains that coloured water additives will discolour your tubes and water blocks. This is annoying if you want to change the colour of your coolant. If you want to avoid this, you have no choice but to always stick to the same colour or simply do without it. <p

Kevin Hofer

Senior Editor

kevin.hofer@digitecgalaxus.ch

From big data to big brother, Cyborgs to Sci-Fi. All aspects of technology and society fascinate me.

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