Weird buildup, how to clean?

[Nacknime]

Hi guys,
I've been running a custom waterloop for about a year. It started to develop some problems with cooling, that got worse over time. There were issues with the waterflow, and now that I took it apart I found that in the tubes, there is some buildup of a white substance. It's especially bad in the graphics card coolers. I'm attaching a picture of the graphics card coolers.
How would you go about cleaning this loop and preventing the same problem to happen again? If the GPU blcoks aren't recoverable, I'd at least love to keep the rest.

Specs of the system:
Bay Pump/Res combo: EK-DBAY D5 PWM MX Acetal
CPU Block: Watercool HEATKILLER IV PRO Copper An
GPU Blocks: EKWB FC980 GTX Ti STRIX Nickel
GPU connector: EK-FC Terminal Dual Serial
Radiators: 2 Alphacool NexXxoS
Tubing: Primochill PrimoFlex Advanced LRT
Coolant: Distilled Water with Mayhems Biocide

Could I maybe have put in a wrong amount of biocide? Or is there maybe some incompatible metals reacting?

Thanks very much for your help.

 

[don256us]

I'm wondering if you have some form of galvanic corrosion going on here. This is caused when two dissimilar metals come in contact with each other. The water would act as the connection. For example, in your car, antifreeze is used to stop this galvanic reaction. However, antifreeze also reduces the ability for the water to carry heat which is why it is not used in cooling loops for computers. If you have copper blocks and aluminum radiators as an example, this would explain your issue.

Since I haven't water cooled for a very long time, I don't know what products are available for this purpose. I also am not sure what to use to clean it but I'm thinking something along the lines of vinegar.

 

[Nacknime]

I'm wondering if you have some form of galvanic corrosion going on here. This is caused when two dissimilar metals come in contact with each other. The water would act as the connection. For example, in your car, antifreeze is used to stop this galvanic reaction. However, antifreeze also reduces the ability for the water to carry heat which is why it is not used in cooling loops for computers. If you have copper blocks and aluminum radiators as an example, this would explain your issue.

Since I haven't water cooled for a very long time, I don't know what products are available for this purpose. I also am not sure what to use to clean it but I'm thinking something along the lines of vinegar.

I was aware of this possible issue, that's why I checked for possible aluminum in the loop.
EKWB has confirmed that in all of the parts I ordered from them, there is no aluminum contained (or if it is, it doesn't come into contact with the water). The Alphacool NexXxoS radiators are full copper. The CPU block is made from stainless steel, so no problem there either.

 

[exadeuce]

Did you have a silver killcoil in the loop? Those can react with nickel I believe.

 

[GTXJackBauer]

First and foremost, to OCFs.

I will say, it doesn't look like there's any aluminum in your loop based on the listing you gave us. Take it apart and clean it with distilled water. Not sure if I would expose any type of acid (ketchup) on a exposed wound, if you will.

EK has stated and warned folks from using distilled water with w/e biocide. Their GPU blocks I at least have seen, end up having issues constantly. I've been trying to promote clear premixed fluids from reputed custom water cooling companies while having some resistance from other's about it here and there. Not calling you out but speaking here in general, I can't stand folks trying to save $20 annually when they've spent hundreds if not thousands of dollars on water cooling, only to save $20 and ruining their loop. Yeah there's a few that never had issues or so they say. I had a great loop for years with distilled with a silver kill coil but lost a few fittings to oxidization and had to scrub clean a few CPU blocks because of it. I got tired of it and went premixed. Haven't looked back since and have the confidence of the liquid in my loop.

Once you clean up, I will recommend to grab some clear premix fluids from EK.

 

[mokrunka]

Just a note that ANY two dissimilar (i.e. different positions on the galvanic series chart) metals can cause galvanic corrosion as don256 mentioned above. Some reactions will take place faster, but it depends how different the cathode/anode characterstics of the materials are. So you could in fact be seeing galvanic corrosion in your loop, even if there is no Al.

I would install a silver kill coil on top of what EK recommends, as others have suggested.

 

[Nacknime]

GTXJackBauer: Thanks for the tip about EK & Distilled, I'll definitely fill up with proper EK fluid after cleaning. Would you suggest a kill coil on top of it?

mokrunka: EK coolant + kill coil? Or is it like with condoms, double protection = less safety?

Generally: Regardless of which fluid to clean with, what tools do you use? How do I get into tight spots, for example fittings?

 

[GTXJackBauer]

The proper fluids don't need anything. Not sure if I would add a silver kill coil as it might throw off the liquids balance is my guess.

The tools we usually use are toothbrushes and I even went as far as getting those metal brushes. I think it was a brass brush I used on my CPU block once it needed cleaning from all the oxidization during my distilled and silver coil days.

IIRC, EK warned about using silver in loops with their nickel blocks as it doesn't jive well.

 

[Nacknime]

Thanks everyone, I'll clean out everything when I get the time and order new tubing, coolant etc.
Will report back when everything is ready to install

 

[Blaylock]

For what it's worth Watercool does not recommend silver in the loop either.

 

[mokrunka]

Interesting, I've always used distilled + silver kill coil with good results for years. I've always stayed away from colored liquids or anything other than distilled.