Every planted tank thread replays the same argument: Week Aqua delivers most of a Chihiros for a fraction of the money — or the fraction of money is exactly the problem. Both camps have real evidence.
Here is the uncomfortable truth: the two lights are closer in raw performance than their price tags suggest. The real gap is in everything around the light — build consistency, the app, support, and where you can buy one. That is what you are choosing between.
Short answer: For the best spectrum-per-dollar, Week Aqua wins: its M and P series use RGB diode layouts comparable to fixtures costing twice as much, with around 200 µmol of PAR at the substrate on a 60 cm tank at full power. Choose the Chihiros WRGB II Slim instead for proven build quality, a better app, and easy retail availability. Week Aqua rewards bargain hunters who tolerate quirks; Chihiros rewards buyers who pay for reliability.
Why These Two Brands Keep Getting Compared
Both Week Aqua and Chihiros build narrow-spectrum RGB fixtures: lights heavy on red, blue, and green diode peaks with few plain white LEDs, which is what produces the vivid reds that budget white LEDs wash out. The 2Hr Aquarist’s 2026 LED guide places both brands in that top tier alongside Twinstar, ONF, and ADA.
They promise the same thing: a premium look and genuine growing power for demanding plants. Week Aqua undercuts Chihiros on price by a wide margin; Chihiros carries the brand, the dealer network, and the track record.
The Case for Week Aqua: Same Spectrum, Lower Cost
Week Aqua’s pitch is simple and, on the light itself, largely true. The M and P series use RGB diode arrangements comparable to fixtures costing far more, with the M600 measuring close to 200 µmol of PAR on the substrate of a 60×31×36 cm aquarium at full power — high-tech territory, enough for HC Cuba carpets and demanding red stems.
The honest part: the same source ends its Week Aqua praise with a caveat — “quality is far more unreliable.” Owners report dead sections on arrival, and the app, while functional, carries the non-intuitive logic common to China-made hardware apps. Buying is the third friction: vendors are limited outside Asia, and many buyers wait weeks for AliExpress shipping.
The P-series is the sweet spot for most 60–90 cm tanks. As an Amazon Associate I earn from qualifying purchases — this is how AquaVerdia stays free. The Week Aqua P Series P600 PRO ★4.5 is a fitting flagship pick with a strong Amazon review profile.
The Case for Chihiros: Proven Output and Better Support
Chihiros is the brand people buy when they are done experimenting. The WRGB II Slim line is the gentle entry: the 60 cm model runs 45 W and 2,400 lumens — plenty for a low-to-mid-tech 60P — while the full WRGB II steps up to 67 W and 4,500 lumens for high-demand tanks. The story is the same across the range: measured output that matches the spec sheet, wide even spread, and RGB 3-in-1 diodes that render reds beautifully.
Where Chihiros pulls away is ownership. Its app is stable and easy to program — a real difference if you touch the schedule weekly. Support has a track record: when users flagged a flaw in the Commander 4 controller, Chihiros shipped a revised version within months. And the lights are stocked by aquascaping retailers worldwide, so a dead-on-arrival unit means an exchange, not an international dispute. The trade is cost — Chihiros commands a premium at every size.
The Chihiros WRGB II Slim ★4.5 is the sensible default: full-spectrum WRGB output, Bluetooth app control, and a 4.5-star Amazon rating.
Week Aqua vs Chihiros, Head to Head
| Week Aqua | Chihiros | |
|---|---|---|
| Spectrum | Narrow-band RGB (+UV on newer models) | RGB 3-in-1 diodes, tunable WRGB channels |
| Output (60 cm) | ~200 µmol PAR at substrate (M600, full power) | Slim: 45 W / 2,400 lm; WRGB II: 67 W / 4,500 lm |
| App | Functional but clunky | Polished, stable, easy |
| Build & QC | Spotty — inspect on arrival | Consistent and sturdy |
| Support | Limited and slow | Responsive, real warranty |
| Availability | AliExpress + niche vendors, long shipping | Stocked worldwide |
| Cost | Noticeably cheaper | Premium |
Which Should You Buy?
Skip the brand loyalty and match the light to your situation:
- Buy Week Aqua if you run a 60–90 cm CO2-injected tank, want maximum red color and PAR per dollar, and can live with a fiddly app and a harder warranty path.
- Buy Chihiros if reliability, a good app, and easy returns matter more than saving money — or if you are outside the main supply corridors.
- Buy neither if your tank is low-tech without CO2. Both are overkill for Anubias-and-Java-fern setups; a dimmer-friendly budget light from our low-tech lighting guide grows those plants and starves algae far better.
FAQ
Is Week Aqua really as good as Chihiros?
For the light itself — spectrum and raw PAR — yes, surprisingly close. For build consistency, app quality, support, and availability — Chihiros is clearly ahead. The premium buys fewer headaches, not more photons.
Which Chihiros model matches a Week Aqua P600?
The standard WRGB II (67 W / 4,500 lm at 60 cm). The WRGB II Slim (45 W / 2,400 lm) is gentler — better for shallower or less demanding tanks. Compare them in our Slim vs Pro guide.
Can I use these lights on a low-tech tank without CO2?
You can, but dim them to 40–50% with a 6–7 hour photoperiod. High light without injected CO2 grows algae faster than plants, regardless of brand — a cheaper dimmable light is the smarter buy for low-tech setups.
Is the Week Aqua app really that bad?
It works — timers, dimming, and spectrum presets all function — but the logic is unintuitive and first setup frustrates many owners. If you adjust lighting often, Chihiros’ app alone justifies the premium.