White spots on replaced water tubing

[Olaf6541]

Hi all,
Its been a while, but finally had the time to do maintenance on my build and change the tubes. 
I already noticed it before, but now I replaced the tubing I finally have a good view on the old tubes. 
There is a white residue caked on the inside of the tubing.

 

It is mostly caked on the inside of the tubes, blocks don't seem to have it. 
Its also in some of the tubes, not all. The fluid was blue, but this residue is bright white (with some blue stains from the fluid ofcourse).
It does not come of easily, need to scraped. But the tubes itself don't seem to be damaged.
Most of it was stuck on the tubes, only a very small amount was in the fluid.
Is this just broken down coolant additives or is it from the tubes itself?

 

Bonus images: some of it also leaked onto the usb dock. Can easily be scraped off with a toothbrush, the plastic is not damaged.

 

https://imgur.com/a/DtRuHSB

 

- EK cryofuel concentrate (navy blue I think)
- EK DuraClear tubes (16mm/12mm)
- EK CPU/GPU supremacy blocks, EK Coolstream rads, EK dual bay res + D5 pump
- Its been in there for about 3 years, occasionally topped off with more demineralised water
 

[jaslion]

Was it blue opaque or blue transparent fluid? What fluid did you use now? Might need some biocide in the tubes.

 

I recommend you fully flush your loop multiple times and fill it up again with deminiralized water + biocide or get a off the shelf coolant that has it in it.

[Olaf6541]

49 minutes ago, jaslion said:

Was it blue opaque or blue transparent fluid? What fluid did you use now? Might need some biocide in the tubes.

 

I recommend you fully flush your loop multiple times and fill it up again with deminiralized water + biocide or get a off the shelf coolant that has it in it.

It was transparent, I now use the same EK cryofuel but clear transparent, not colored.

I replaced all tubes, flushed the rads and blocks and filled it back up with demi water and concentrated EK cryofuel.

I'm just curious what the white stuff is...

[andrewmp6]

I believe its plasticizer from the clear tubing,The only clear tubing that will stay clear forever is tygon tubing.The rest say they won't plasticzer but do in time.The other option is colored tubing which don't do this either.