I have a liquid cooled GPU, after running for about a month, a leak happened and the whole system shutdown - Having drained the system, I note that there is a black powdery deposit in the reservoir. The system consists of deionised water passing through: a copper water block, PVC tubing, aluminium radiators, plastic reservoir, pump, silver kill coil with joints made from Nickel coated brass. All of the parts are specifically sold as being for water cooling systems but I understand that disparate metals in a liquid loop can lead to electrolytic degradation.

What materials in this system (aluminium, silver, nickel coated brass) are liable to electrolytically degrade in a deionised water loop with copper and need to be replaced?

  • Ionization shouldn’t have happened in a month. Of course the leak shouldn’t have happened either.
    – Ramhound
    Aug 30, 2018 at 14:33
  • Not entirely sure a full treatment of galvanic corrosion is on topic here but ya, that's what you're looking at. Totally not a computer but similar issues I suspect. However, iof its black, are you sure its not something else? maybe some release agent on plastic parts?
    – Journeyman Geek
    Aug 30, 2018 at 14:37

1 Answer 1


Copper block and aluminium radiators are known to cause galvanic corrosion (=>electrochemistry). You probably need to exchange the radiator(s) for copper or nickel type.

AIO manufacturers use a lot of anti-corrosives in their fluid mixtures in order to achieve a "safe" 2 year warranty period in mixed metal loops. But these chemicals only slow down the reaction and cannot completely prevent it AFAIK.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.