Coolants for custom PC water cooling loops: ready-to-use premixed fluids, concentrates that are diluted with distilled water, and clear, dyed or opaque variants. The range suits builders filling a new loop or refreshing an existing one, with products from EK Water Blocks, Alphacool, XSPC and Aqua Computer.
How to choose a PC coolant
Premixed or concentrate. A premixed coolant can go straight into the loop, which removes the risk of getting the dilution wrong. A concentrate costs less per litre of finished fluid, but you need distilled water and must follow the mixing ratio on the label.
Metal compatibility. Check which metals the coolant is designed for. Loops with copper and nickel-plated parts are the usual case, while any aluminium component needs a fluid that explicitly protects it, because mixed metals can corrode.
Clear, dyed or opaque. Clear and dye-based fluids stay thin and flow freely through fine cooling fins. Opaque or pastel fluids rely on suspended particles for their colour, so they can settle over time and are harder on narrow-channel blocks. Choose these only if the look matters more than low maintenance.
Tubing and loop material. Some coolants react with soft PVC tubing, leaving residue or discolouring the fluid. If you use flexible tubing, look for a coolant the manufacturer states is compatible with it, or choose rigid tubing.
Volume. Most loops with one CPU block, one GPU block and a couple of radiators hold roughly a litre or less, but a large reservoir or several radiators need more. Buy a little extra for topping up and for flushing during the first fill.
Coolant brands in our range
- EK Water Blocks: a Slovenian specialist in water cooling, known for its EK-CryoFuel fluids, which are sold as premixes and concentrates in several colours.
- Alphacool: a German manufacturer that covers a whole loop, from radiators to fittings, and sells coolants designed to match its other parts.
- XSPC: a water cooling brand known for complete kits and its own range of coolants for them.
- Aqua Computer: a German maker whose Double Protect Ultra fluid is aimed at long service intervals and mixed-metal loops.
- Innovatek: a German water cooling company with a long history in PC liquid cooling and its own range of coolants.
Also in our range: Stealkey Customs and some unbranded coolants.
Coolant FAQ
How often should I change PC coolant?
Many manufacturers suggest replacing coolant roughly once a year, although some long-life fluids state longer intervals. Change it sooner if the liquid turns cloudy, shows particles or leaves deposits in the reservoir. The label on the bottle gives the figure for that specific fluid.
Can I use distilled water instead of coolant?
Distilled water works as a short-term filler, but it contains no corrosion inhibitors or biocides. Over time this allows corrosion and microbial growth in the loop. A proper coolant or a correctly diluted concentrate protects the metal parts and keeps the fluid clean for longer.
Can I mix different coolants?
Mixing coolants is generally not recommended. The additives in different formulas can react with each other and cause cloudiness, sediment or reduced corrosion protection. When switching brands, drain the loop and flush it thoroughly first.
Is PC coolant safe if it leaks onto components?
Not necessarily. Some coolants are sold as non-conductive, but fluid in a used loop can pick up dissolved metals and conduct electricity. Switch the system off, disconnect the power and let everything dry completely before powering up after any leak.
