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QUICK VERDICT
Our picks at a glance
The AI Prime 16HD is the compact light to beat on value, the Red Sea ReefLED G2 60 is the easy choice for a 45–50cm cube, and the EcoTech Radion XR15 G6 Pro is the premium pick with the most flexible control.
Best value compact light
AI Prime 16HD Reef
£239–£260
Compact 40–50cm nano tanks
Search Amazon UK ↗Best for a 45–50cm cube
Red Sea ReefLED G2 60
£269
An easy pick for a 45–50cm cube
Search Amazon UK ↗Best premium light
EcoTech Radion XR15 G6 Pro
£464–£465
Premium control for 60cm-wide tanks
Search Amazon UK ↗OUR PICKS IN DETAIL
Who each one is really for
Best value compact light
AI Prime 16HD Reef
Best for
Compact 40–50cm nano tanks
Why we picked it
59W; Up to 61 × 61cm; UK sellers commonly narrow this to 50 × 50cm; myAI app; control built in.
The catch
The cost of a mount, and how well it lights the edges, can change how good a deal it really is.
Yes, for a 40–50cm tank, once you’ve checked the price with a mount included.
Search Amazon UK ↗Best for a 45–50cm cube
Red Sea ReefLED G2 60
Best for
An easy pick for a 45–50cm cube
Why we picked it
60W; 50 × 50cm test footprint; maximum stated water depth 50cm; ReefBeat app; app-led setup.
The catch
The published coverage is a starting point, not a guarantee for every spot in your tank.
Yes, if your tank’s shape suits it and you’re happy using Red Sea’s ReefBeat app.
Search Amazon UK ↗Best premium light
EcoTech Radion XR15 G6 Pro
Best for
Premium control for 60cm-wide tanks
Why we picked it
95–105W listed; 61 × 61cm recommended; up to 76 × 76cm maximum claim; Mobius app built in.
The catch
A premium price, and up to £100.08 at 105W a year in electricity if run at full rated power in our comparison.
Yes, if the extra programming and coverage options are worth the premium over the compact lights.
Search Amazon UK ↗HOW WE RESEARCHED
How we chose
We compared manuals, manufacturer specifications, current UK retailer listings, running requirements, ownership costs and support. This is desk research, not hands-on testing, and where something is uncertain we say so.
- Coverage for your tank size
- Power and running cost
- Cost of mounting it
- App and control
- Current UK stock
The short answer
The AI Prime 16HD is the compact light to beat on value. The ReefLED G2 60 is the neatest choice for a 45–50cm cube, especially a Red Sea one. The Reef Flare Pro S claims the widest coverage at around this price. The Kessil A360XE is all about natural-looking shimmer, while the Radion XR15 G6 Pro is the premium pick with the most flexible control. The right one still depends on your tank’s size and where your corals sit.
| Light / checked price | Power / claimed coverage | Control | Best for / max yearly running cost |
|---|---|---|---|
| AI Prime 16HD Reef £239–£260 | 59W Up to 61 × 61cm; UK sellers commonly narrow this to 50 × 50cm | myAI app; control built in | Compact 40–50cm nano tanks £56.22 electricity |
| Red Sea ReefLED G2 60 £269 | 60W 50 × 50cm test footprint; maximum stated water depth 50cm | ReefBeat app; app-led setup | An easy pick for a 45–50cm cube £57.18 electricity |
| Reef Factory Reef Flare Pro S £299 checked; lower sale prices seen | 80W Up to 60 × 60cm, to 60cm depth claimed | Smart Reef app | Wider nano tanks; check sale stock £76.24 electricity |
| Kessil A360XE Tuna Blue £459.90 | 90W 61 × 61cm mixed reef; 51 × 51cm SPS claim | Manual control; Wi-Fi dongle or controller for programming | Natural shimmer, with optional programming £85.77 electricity |
| EcoTech Radion XR15 G6 Pro £464–£465 | 95–105W listed 61 × 61cm recommended; up to 76 × 76cm maximum claim | Mobius app built in | Premium control for 60cm-wide tanks £100.08 at 105W electricity |
What the price doesn’t include
Price up the tank arm, hanging kit, rail, shade or diffuser before you compare. A cheaper light can lose its edge if the mount you want costs another £50–£100. Kessil also sells programmable control separately from the light, while the other four run from their own apps.
How we worked out the electricity
The yearly figures are a deliberately cautious worst case: rated watts × 10 hours a day × 365 days × 26.11p/kWh. In practice you’ll spend less, because lights ramp up and down and rarely run at full power. Use the electricity calculator with your real schedule and tariff.
Sources and limits
We checked technical claims against AquaIllumination, Red Sea, Reef Factory, Kessil and EcoTech product information. Prices come from Porton Aquapet, Burscough Aquatics, Finest Aquatics, Watermarque and All Things Aquatic. We haven’t measured PAR, spectrum, fan noise or long-term reliability ourselves.
WHICH ONE FITS YOU?
Buy for the reef you can actually light
A shallow soft-coral reef
A modest light with even coverage can be more useful than a concentrated high-output one. Prioritise dimming, a sensible mounting height and enough spread to avoid dark edges as corals grow.
A mixed reef that keeps changing
Choose a light you can control, with enough spare output to acclimatise new corals without running it flat out. On a wide tank, two lights often give better coverage than one intense light in the middle.
An SPS-dominated reef
Light spread, mounting position and measured intensity become critical. Plan to measure with a PAR meter (or borrow one), because manufacturer maps and wattage can’t tell you how much light reaches each coral in your rockwork.
HOW TO CHOOSE
What to check before you buy
Match the light to your footprint
Compare your tank’s inside length and width with the light’s useful spread at the height you plan to mount it. Braces, lids and rock islands can all change the result.
Watts aren’t usable light
Watts measure the electricity going in, not the light your corals can use. Optics, spectrum, mounting height, water clarity and surface movement all affect what reaches them.
Check how it’s controlled
Find out whether schedules need an app, a separate controller, a cloud account or a permanent connection, and whether the light keeps its programme after a power cut.
Plan to acclimatise
Start a new light below your final target and increase it gradually. How your corals respond, and what you measure, are better guides than copying someone else’s percentages.
RUNNING COSTS
What it costs after you buy it
Electricity
Base your estimate on the power and hours you actually programme, not the maximum wattage. A long sunrise ramp doesn’t mean the light runs at full power all day.
Mounts and shades
Arms, hanging kits, diffusers and glare shades can add significantly to the cost. Price every part you need for where the light will go.
Heat and servicing
Fans gather dust and can get noisy; fanless lights avoid that but still need airflow. Check how UK warranty claims work and whether replacement power supplies are available.
ALTERNATIVES
Other options worth a look
Two smaller lights
A pair can improve coverage at the edges and reduce shadows, but means more cables, more mounts and a higher total cost.
Adding LED bars
LED bars can fill gaps in spectrum or coverage around a main light. They’re harder to control in some setups, so price them as part of the whole system.
HOW WE RANK
What it takes to make our list
It has to fit
Before we compare features, we rule out anything that doesn’t suit the tank, the installation or the job. A famous name can’t win if its size, operating range, connections or controls make it a poor match.
Claims need context
A spec sheet tells you what a product is designed to do, not how it will behave in your reef. So we look at the conditions behind every capacity, flow, output and accuracy claim, and flag any conclusion that’s an informed judgement rather than a measurement.
Every pick shows its catch
Each product’s main drawback sits right next to its biggest strength. We don’t hide a support worry, a missing accessory, a vague rating or a pricey ecosystem just because the product is the best choice for one type of buyer.
UK ownership breaks ties
Availability, what’s actually in the box, consumables, spares, UK plugs and the warranty route all count. When two products do the job equally well, the one that’s easier to own in the UK gets the stronger recommendation.
We don’t publish a one-size-fits-all league table. Each award answers a different buying situation, and the final verdict explains which trade-off we’d make. If your tank, budget or routine doesn’t match any of them, use the checks above to build your own shortlist rather than just buying the top badge.
COMMON QUESTIONS
Frequently asked questions
How many watts does a reef light need?
There’s no reliable watts-per-litre rule. Tank depth, footprint, optics, spectrum, mounting position and what you keep matter far more.
Can a reef light be too powerful?
Yes. Too much intensity, or too sudden a change, can stress corals. Spare output is only useful if you can control it and acclimatise carefully.
Do I need a PAR meter?
Not for every soft-coral tank, but it takes the guesswork out of mixed and SPS reefs. Borrowing or renting one for setup and big changes is often enough.
BEFORE YOU ORDER
Three checks before you pay
Confirm the exact model
Shop listings often mix up generations, sizes and regional versions. Check the full model code, UK plug, included accessories and who handles the warranty against the manufacturer’s own details. Save the product page and spec sheet in case the listing changes.
Price everything it needs
Add the mount, controller, adapters, consumables, test kit and likely replacement parts you’ll need to run it. Compare that first-year total, not the headline price, and keep a little extra for plumbing, cable tidying or the fitting you forgot.
Measure twice at home
Measure your tank, cabinet, sump chamber, glass, sockets and the space you need to service it. Then write down the one job this kit has to do, and how you’ll know it’s working. If it won’t fit, or you can’t tell whether it’s doing its job, it’s the wrong choice.
Prices and stock change quickly. Every price here is a dated UK snapshot, so confirm the total at checkout and the returns terms, and don’t swap in a similarly named model without running these checks again.
OUR VERDICT
Coverage beats maximum output
Shortlist by your tank’s size and the corals you want, then compare the full price with mounts. The best light is the one that delivers even, measured light across your whole aquascape, with output to spare and support you can get in the UK.
Once it’s running, note any lighting changes in the free Reef Companion alongside your water tests, so you can connect cause and effect when corals respond.