Which metals experience electrolytic degradation with copper in a dionised water GPU cooling loop?

Question

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?

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.