I want to publish this build mainly because it uses 13mm / half inch hard tubes in a Fractal Design Define R5 case. Most builds on the Internet are either with 16mm tubes or do not specify the tube size. When I was deciding which tubes to go with, it would have been nice to see some examples of 13mm tubes in a Define R5.

The main reason for going with 13mm tubes for me was that this was a conversion from soft tubes to hard tubes, so I already owned the radiators. Unfortunately these Alphacool V1 radiators did not have enough space for 16mm fittings when a fan was installed on the same side as the fittings (this was discussed at https://www.reddit.com/r/watercooling/comments/167wabz/do_the_16mm_hard_tube_fittings_fit_clear_the_fan/).

What went well:

• the machine is inaudible when idling - to keep the water from making a splashing noise (especially in the Monsta radiator), I filled the loop to the top
  
• it does not look too shabby (the colours in the photos look very different in real life)
  
• combining the two above: the Noctua fans are very good, even though they don't match the color scheme (not going to replace them with the black variants only due to cosmetic issues - I did buy the black accents though [and spray painted a couple brown ones])
  
• the Define R5 case is of the correct size for a build like this - anything smaller would be too small. The HDD cage has been removed (not by force, the case is modular)
  
• the EK CryoFuel Navy looks very good and if it leaks, you'll see the dried blue leak marks notifying you where the leak originated (the glass is always half full )
  

Even better if:

• the Alphacool NexXxoS Monsta 120mm radiator is not the best product I've ever bought, should have gone with the 30mm or 45mm thick variant. It makes noise if not filled to the top and I'm not too sure about the performance gains either. On the bonus side, it does have a fill port on the top, which is very useful
  
• the Barrow ball valve could be of a better quality: it is very stiff and it is not flat in the inside (creates some resistance in the flow)
  
• behind the reservoir there is an EK Quantum Torque Drain Valve from 2022 and it has started leaking. The cap does not have an o-ring, so I replaced that with a regular G 1/4 inch plug with an o-ring
  
• this was my first hard tube build and coming from soft tube builds, I was accustomed to the compression fittings being very pull resistant. However these Alphacool Hardtube compression fittings do not hold the tube in place with great force - it is easy to pull the tube out even without unscrewing the fastening part of the fitting first. This is an issue only with the tube going from the GPU to the ball valve, as that tube could be accidentally hit and it might come off. I might replace the fittings in that tube with Alphacool Eiszapfen PRO fittings to try if those hold the tube in better (just to note that the PRO fittings are too large in diameter to be used with these radiators)
  
• the AMD Ryzen 5900X is too powerful for my use cases - could have gone even with a 5600X with lower heat output (to lower noise), but at least this is a more "futureproof" machine if that is even possible. I'm running the 5900X in 65W eco-mode for now (just to note that most parts were bought in 2021, including the CPU)
  
• the exposed Samsung SSD runs hot when in heavy use - will add an after market heatsink on top of that at some point
  

Trivia:

• the Barrow ball valve is for calibrating the virtual flow sensor in the Aquacomputer D5 Next pump
  
• there is a serial port on top of the PSU - good for configuring Cisco network devices, for example
  
• similarly there is a floppy drive with internal USB adapter, spray painted black
  
• the device next to the floppy drive is an ESP8266 module with a relay used to remote control the power of the machine (https://github.com/iivorait/esp8266-power-remote-control). WOL isn't quite working for me, and with this module it is possible to send shutdown as well as hard shutdown signals (long power button press). Parsec is then used for 3D accelerated remote desktop