What is the best UV water-cooling coolant?

Coollaboratory Liquid Coolant Pro UV

Manufacturer: Coollaboratory
UK price (as reviewed): £8.98 (inc VAT)
US price (as reviewed): N/A

Coollaboratory is better known for its interesting liquid metal thermal pastes than for pre-mixed coolant, but the company has had a few variations of the latter around for some time now. The Liquid Coolant Pro range is available in both pre-mixed and concentrate forms but just in blue, UV blue and green varieties.

Our green sample proved to be fairly vivid in normal light, although the Nanoxia Hyperzero was noticeably more so. The latter was also more vivid under UV light. Like most of the coolants on test, it's advertised as providing corrosion protection and Coollaboratory claims you shouldn't need to change the coolant for at least 24 months.

It proved to have the best thermal performance of any other coloured coolant on test, with a delta T of 29°C, although this was only 3°C better than the worst performing coolants on test, which were pure deionised water and PrimoChill ICE UV Pink,which recorded delta T's of 32°C. Flow rates were very similar across the board and the Coollaboratory Liquid Coolant Pro UV was no exception.

It's cheap enough, and did seem to perform better, but only marginally so. As the Nanoxia Hyperzero coolant looks better and is cheaper too, we'd suggest it is the better option, unless you're desperate to squeeze every last degree from your cooling system.

EK-Ekoolant UV Lime Green

Manufacturer: EK Waterblocks
UK price (as reviewed): £6.25 (inc VAT)
US price (as reviewed): N/A

EK is well known as being one of the leading manufacturers of waterblocks and more recently radiators and reservoirs, but it also has a range of pre-mixed coolants too. The EK-Ekoolant UV range has anti-algae and anti-corrosion additives and EK also claims it has low electrical conductivity.

The EK-Ekoolant UV Lime Green was fairly disappointing when it came to colour and UV reactivity, where the Nanoxia coolant was far better in normal light and under UV. It did show a minor advantage in the flow rate tests, although this didn't lead to an advantage in thermal performance.

It's very cheap, costing little more than bare deionised water and a decent additive, but no coolant will remain completely non-conductive so EK's claims about 'low electrical conductivity' aren't worth a second thought. Unfortunately, the Nanoxia Hyperzero coolant looks better and is cheaper still, so despite costing just £6, there's little to actually recommend it.