EK-CryoFuel Clear Concentrate 100mL for PC Water Cooling Loops, Mix with Distilled Water to Make 1L Coolant, Corrosion Protection Liquid

Does exactly what you expect, I have a full EK custom loop with metal hardline, I contact EK prior to a lot of the build to make sure I wasn't going to get metal contamination from the metal hardline and adding this just makes life a whole lot better when it comes to maintenance time. You should always have this or something like it in your system.

Its hard to tell came back to me in a year or two. Then i can tell you

I don't have bad experiences with EK products, whether the coolant, fittings or waterblocks. They are just a decent make. This bottle does what it needs to when added to deionised or distilled water. They cost what they cost and EK products are expensive for some. Other products will get the job done, although you're likely cooling expensive products and you're mixing water and electrics. You should go for quality and that is what EK offers. However, you don't need to spend a lot to get that quality (and I have other products in my machine too. This concentrate bottle is fine but I would buy the pre-mix set. This bottle has a 100ml volume to be mixed with 900ml deionised/distilled water. So 1:9. It will be used up in one mixture. I will just buy their pre-mix solution in future.