EKWB EK CRYOFUEL Loop Cleaner CONC. 250 ml 3831109897690

A little expensive but it's a good product. Easy to use.

I have a small loop, cpu with a EK Quantum Vector block, 240mm radiator. I clean my system every 6 months and don't use colored coolant. Just mix this concentrate with 1 gallon of distilled water and it should last for a year. It does a good job of cleaning, my cpu block and tubes look clean. Soft tubes do get stained over time, next clean up I'll do a complete tear down to see if there's any discolor inside the cpu, radiator.