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Component Choice Advice for a Water Cool Loop

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New Member
Sep 26, 2019
Hello! This is my first post. I found lots of good advice on this forum and was able to pick out pieces for my first ever water cool loop, but now need some advice from you experts :)

Case| NZXT H210
CPU Cooler|Optimus Signature V2
Barbs|Optimus Barb Fitting fitting 10mm internal diameter hosing
Clamps|Optimus Hose Clamp fitting 16mm outside diameter hosing

Pump and Reservoir Combo
I've been looking at this list of EKWB combos, but I'm out of my depth :)
  • My case can support a 150mm maximum height item.
  • I am looking for a D5 pump and reservoir combo with G1/4 threading.

GPU Cooler
I have a AMD Radeon 5700 XT graphics card and have been contemplating this EKWB water block. Is there a water block for the 5700 XT that has better cooling performance?

Given the following points and the fact that I have Noctua NF-A12x25 fans what is the best radiator to order? I read something about static pressure fans and some other type of fan, but I don't really understand.
  • The maximum height is 240mm to hold two 120mm fans.
  • The maximum depth I've measured to be 38mm deep.
  • I have read here that Hardware Labs makes the best radiators.

Hose Clamp Pliers
I have hose clamps I won't be able to close by hand. Are these pliers appropriate? Any better pliers at a better price?

Hosing and Fluid
  • I read someone recommending distilled water mixed with primochill liquid utopia. Does anyone have a good suggestion for long term cooling without damaging any items?
  • Given the barbs and clamps I've purchased I need 10mm ID/16mm OD hosing. I think I prefer soft hosing. Any recommendations?

Thank you for reading my post!
Wow this looks like an exciting build. Can you please post a list of the planned hardware for the PC you intend to cool, as well as including what you have or do not have currently. I have a lot of feedback for you, and I intend it all in a very positive light. I remember how exciting but also how daunting it was to plan my first loop. If someone here suggests that something might not work, it's not that we're trying to be negative, only trying to make the process go as smoothly for you as possible. Most importantly, remember to have fun.


When I went to design my first WC build last year, I was excited to see so many cases with radiator compatibility listed, and essentially assumed that if it could fit a rad, it was a good case for a custom loop. Some Senior members here gave me the excellent advice to think bigger.

Is the H210 a case you already own, or one you're planning on purchasing? I would look at getting a larger case specifically oriented towards a custom loop. Trying to fit a custom loop into that case will be a challenge. Furthermore trying to fit enough radiator into that case for a CPU + GPU loop is going to be next to impossible.

I've never heard of signature before, but that's cool to see another player in the game!

For fittings I would suggest compression fittings vs barb and clamp. They simply look much better. I know they are expensive, but in the end I think you'll appreciate the appearance of it. There's nothing technically wrong with barbs as long as you use the appropriate size (true for any fitting) and some kind of clamp, though.

Pump and Reservoir Combo...

First option is RGB, do you want it or not. Next is PWM. PWM is nice for increasing loop flow as loop temperature increases, but that doesn't have a huge impact on performance. I prefer the D5 Vario, which can be adjusted and set with a screwdriver. This makes filling your loop easier as you can run it slow during filling, and then adjust the speed back and forth to help eliminate bubbles. If the PWM pump is controlled by the motherboard, you won't be able to control the pump speed during filling and leak testing. If you want to go the Vario route, it looks like you might actually spend a bit more because it's not a combo. You'd need the res and pump top, pump, and mounting hardware.

GPU Cooler...

Blocks in general, especially GPU blocks, all have pretty good performance. I wouldn't worry about which full coverage block got a couple C better in one test. In other words, I think the EK block would be just fine, EK makes great GPU blocks. The ever important junction temp is going to depend on mounting technique and paste application more than block design.

It is important to note that the block appears to be designed for reference PCB only. Most blower cooler design cards should fit it, but double check their compatibility listing. The AIB manufactures (ASUS, MSI etc) use different PCB designs across the range of their cards, both reference (based on the AMD release version) and custom ones. In other words, the specific model of graphics card that you have will determine what (if any) GPU block will work with it.

HL rads are great, as are Alphacool (although they tend to require more cleaning, but you should clean all of your rads anyway). Is your depth measured to include fans or not? Rads usually come in 30mm, 45mm, and 60mm thickness. With a 38mm space you'll need a 30mm rad such as the Hardware Labs Blaack Ice Nemesis GTS.

There are two guidelines for determining how much radiator capacity a loop will require. One is 120mm for each water cooled component or 240mm for each overclocked water cooled component. By this measure, the 240mm would be adequate for a CPU+GPU loop with ZERO overclocking. However I believe a more useful metric is to use 120mm per 100W that needs to be cooled. The 5700xt is a 225W card stock and that would increase if OCd. Meanwhile most CPUs are between 100W and 150W stock and increase when OCd. With this latter metric we see that optimally, a 360mm rad would be ideal, even with no overclock.

hose clamp pliers
No idea, I just use needle nose for similar hose clamps on my car, but it's a lot more clumsy and the downsides of slipping are a lot lower in an engine compartment.

hosing and fluid
I use EK cryofuel clear. I would avoid any colors, and use what the block manufacturer suggests. You can also use PT nuke and distilled water, or a silver kill coil and distilled water. It's important to note, however, that there are two kinds of PT nuke. One contains copper sulfate, the other benzalkonium chloride. If you have nickel plating in your loop, it is advisable to avoid using silver or copper sulfate in the loop, leaving only the benzalkonium based ("Petra's PT Nuke) as an ideal option.

You must use flexible / soft tubing with barbs. You should be able to use something like this. Some people have reported issues with the box staining their tubing though with this brand. I would suggest ordering it from http://www.performance-pcs.com/ from their bulk supply to avoid this problem (I would link directly but their site doesn't want to load rn).

I hope this helps you get started. Good luck and have fun!
Thank you for a thoughtful reply! The only components I don't already have spread out on my living room floor are the CPU (on back order), tubing, GPU water block, ball drain, fluid, pump, reservoir, and radiators. Here is the PCPartPicker part list I put together for the individual components.

CPU: AMD Ryzen 9 3900X 3.8 GHz 12-Core Processor
CPU Block: Optimus Signature V2 CPU Block (Intel)
Motherboard: ASRock X570 PHANTOM GAMING-ITX/TB3 Mini ITX AM4 Motherboard
Memory: G.Skill Trident Z 32 GB (2 x 16 GB) DDR4-3200 Memory
GPU: XFX Radeon RX 5700 XT 8 GB Video Card
GPU Block: EK-Vector Radeon RX 5700 +XT RGB - Nickel + Acetal
Case: NZXT H210i Mini ITX Tower Case
Power Supply: EVGA SuperNOVA GM 650 W 80+ Gold Certified Fully Modular SFX Power Supply
Case Fan: Noctua NF-A12x25 FLX 60.09 CFM 120 mm Fan
Case Fan: Noctua NF-A12x25 FLX 60.09 CFM 120 mm Fan
Case Fan: Noctua NF-A12x25 FLX 60.09 CFM 120 mm Fan

The NZXT H210 is an ITX case, but is actually slightly larger than an average ITX case. Some reviewers were tempted to classify it in the next largest category. I've seen water cooled builds with this case and its predecessor the H201 on PCPartPicker. I am confident that the case has enough space for a clever loop :) Here is a quick snap of the case on my floor. It looks roomy!


I really enjoyed reading your advice on the recommended radiators per 100 watts to cool! I will not be overclocking. Given your math I think my 240mm and 120mm radiator setup will be sufficient. I will have a 240mm radiator in the front and a 120mm radiator in the back. The rear radiator will be positioned in the loop between the GPU and CPU to cool the fluid between the GPU and CPU.

I created this mock-up of my case and my planned water cooled component lay-out. The green dots in the mock-up are the tubing connections. The front radiator connections can either be at the top or bottom. I placed them at the bottom in the picture, but will probably have them at the top for easier connection to the reservoir.


I measured the space between the end of my GPU and the case front and found that, from left to right, positioning the fan then radiator gives me a maximum radiator width of 38mm, but reversing the positioning gives me a maximum radiator width of 46mm!


Another user on PCPartPicker had the same idea. I've edited his picture to show the component positions better.


If I hadn't already received my Optimus barbs in the mail I might have purchased compression fittings instead given your advice. I'm not too picky about looks so using clamps is fine to me and I read on Reddit that barbs and clamps are less likely to leak compared to compression fittings. Is that true?

GPU Water Block
Since the performance is all pretty similar I'll order my block from EKWB for convenience. The GPU I purchased is a reference board so I'm sure it'll fit.

Pump and Reservoir
I don't want RGB and PWM sounds nice. I'm hesitant to purchase these separately since the combos seem so much easier for me as a newbie, but you made good points about the Vario, however it is out of stock. I found this combo unit that uses the same reservoir, but with a Xylem D5 pump and it is too tall for my case which means I'd have to mount it horizontally. I'll have to measure later to see if it'd fit horizontally. If I wanted to mount vertically I'd have to get this 150mm tall unit.

Looking at the pictures of the mounts and that white metal strip in my case meant to mount reservoirs I see that I could mount the reservoir horizontally easily, but I'm unsure which mounting bracket I'd need to mount vertically.

Both GPU water blocks use nickel plating so I will avoid using silver like you suggest. I will order EK Cryofuel Clear.

Thank you for confirming that Hardware Labs makes good radiators. I will order their 120mm and 240mm radiators.

Further thoughts
I really appreciate the time you took to share your expertise, Zerileous! You answered many of my questions. I have a few more questions. How should I set up the airflow? Push from the front and pull out the back? Is it even important with a water cooled system? In general should I be pushing into a radiator or pulling away from it?

I'm sure it is possible. If you are determined to have the setup you can sure make it work, especially with flexible tubing. It just isn't what I would typically suggest for a first loop. Once you start putting fittings on things, you'll notice that measurements and sizes don't always add up the way you expected. You could try a 45mm rad, although make sure you check the actual measurements to ensure that it will fit, including thickness, heights and width. I think it would easier to use a 30mm rad. Although some benefit may be noticed from the extra thickness, it isn't the same as having more radiators. For example 1 60mm rad does not equal 2 30mm rads of the same size, in terms of performance.


I guess they are maybe less likely, but the compression fittings are pretty tight as well. The difference is the clamping pressure is applied against the barb instead of behind it, but a tightened compression fitting will apply substantial pressure on the tube to keep it in place (for flexible tubing). The clamps supplied look nice enough, I'm sure it won't detract from your build significantly.

Even though you are using mainly barbed tubing, you may need to use 90 degree, 45 degree or 90 degree dual rotary fittings to avoid kinked tubing in some spots. These can be purchased either as a G1/4 adapter (which would allow you to install your barb to the fitting), or as a specific compression fitting size. You could either purchase an assortment in advance and have extra (they are not inexpensive) in order to facilitate a quicker assembly process, or stop and order them as you go. If you have a Microcenter local to you, they also carry some WC fittings.

yes the 100mm res is a better option then. You could also look at using a DDC pump to save 10mm. https://www.ekwb.com/shop/ek-xres-100-ddc-3-2-pwm-elite-incl-pump#ow_alert_box They are regarded as being a little louder than the D5 but are more compact, and with PWM I doubt you'll notice.
With your further clarification I've decided to order Hardware Labs 30mm x 240mm front and 54m x 120mm rear radiators.

I agree that I will probably need some angled connectors, but I won't know which ones until I have more parts assembled.

Pump and Reservoir
With your advice, and finding that performance-pcs.com has stock, I've decided to buy the EK-D5 Vario pump and the EK-XRES 100 REVO D5 reservoir.

I feel confident in the component list now. Thank you so much for helping me out! :clap: