Coolant is not a cleaner. Every one of these exists so the fluid you fill with can do its actual job instead of scrubbing your loop. Two kits if you want the decision made for you, five bottles if you want to build the sequence yourself.
This is what every bottle above is defending against. The mechanism, the visible symptom, and the product that stops it.
Put copper and nickel in the same wet circuit and you have a battery. Electrons move from the less noble metal to the more noble one, and the nickel plating on your block starts to lift in flakes you will find in the reservoir six weeks later. Temperature accelerates it: a loop that idles at 45 °C corrodes faster than one that never leaves 30 °C.
Liquid Utopia carries a corrosion inhibitor package that plates a molecular barrier onto exposed metal. 15 ml per gallon of DI or distilled — under-dosing is worse than not dosing, because a partial film leaves anodic hot spots.
Every block, radiator and fitting arrives with something on it — machining oil, casting flux, cutting debris. If the first thing to meet that residue is your coolant, the coolant spends its inhibitor package cleaning instead of protecting, and you see the result as a film at week three.
Prepping is ninety minutes. Not prepping is a teardown, and it is almost always blamed on the fluid.

Keeping It Cool is the technical library of PrimoChill. Products ship from primochill.com.
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