What is the best water-cooling coolant?

Mayhem's Pastel Ice White

Manufacturer: Mayhem's
UK price (as reviewed): £15.42 (inc VAT)
US price (as reviewed): $20.99 (ex TAX)

If its straight colour you're after, then Mayhem's also has what it calls a Pastel range of coolants. These are vivid, opaque coolants and as we found with the Ice White version we tested here, they're so opaque that it's likely you won't see any fancy spinning flow meters or waterblock logos through the coolant - worth remembering.

However, this is the only cost as far as we can see, and it's one worth paying as the Ice White looks fantastic. Filling our system looked like a scene in a milk shed in the early hours - the density of colour really does make the Ice White look like milk, and gave our clear tubing a clear white colour, which is probably just what you're after and certainly bodes well for the other colours in the range.

What's more, the coolant seemed very immune to microbubbles, with the system ridding itself of these within a minute or two - a fraction of the time it took most of the other coolants. Performance was similar to the other coolants on test, but as we're now stressing, a vast majority of coolants will perform within a very narrow envelope - with all the coolants we've tested so far, you should base your purchase on looks and value alone.

It's not quite as spectacular as the Aurora Tharsis, but the Mayhem's Pastel range of coolants has the potential to allow you to match your coolant to your case colour theme like never before. Opting for coloured tubing has been the better option in the past, however we expect to see plenty of white-themed projects sporting Mayhem's Pastel Ice White in future.

Phobya ZuperZero Coolant

Manufacturer: Nanoxia
UK price (as reviewed): £10.88 (inc VAT)
US price (as reviewed): N/A
Phobya's range of water-cooling gear is expanding rapidly and now encompasses radiators, waterblocks, pumps and coolants. The ZuperZero coolant is one of the more expensive coolants we've looked at recently, but despite its high price tag, (it's nearly twice the price of the Nanoxia HyperZero coolant we tested recently) it offers nothing in the way of colour, pigment or UV reactivity.

However, Phobya does claim that ZuperZero is completely biodegradeable and contains a lubricant for pumps as well as offering corrosion protection and algae suppression. This isn't anything over and above standard deionised water and a decent additive, though, so at £10.88 a litre, it's still a tad on the expensive side.

As we expected, the ZuperZero clear coolant performed exactly the same as the red version we looked at in our previous roundup - a result that also mirrored all the other coolants we've tested within a very small margin.

Out of the bottle, it undoubtedly ticks all the boxes as far as having anti-algae and anti-corrosion properties are concerned, however we suspect that it's main disadvantage, for old hands at least, is that it's cheaper to use deionised water mixed with an additive if you're not fussed about the added bling UV or coloured coolant will offer.