The Grassy Wing2 is a passively cooled strip light coming out of Japan with a few neat features. It comes in one, two, and three feet long models, with length adjustable mounting legs to fit onto a tank’s side rims. The PCBs are populated with a mix of royal blue, blue, green, deep red, cool white, warm white, UV, and violet diodes which are then grouped into four channels via Bluetooth app control. They don’t use lenses, reflectors, or diffusers, and the mix of CREE and Osram LEDs all run at less than a watt each.
As you might expect the mobile App allows for dimming and timer functions of each channel, as well as weather effects, grouping different lamps together, and sharing settings with other Grassy Wing users. What’s neat though is being able to select one of six coral reef regional lighting cycles like the Caribbean or the Red Sea for example, for enhanced biotopic realism if the user so desires.
Depth control
The app features a useful spectral graph for each channel which peaks and troughs as you adjust the intensity from 0-100% and create your own perfect blend of UV, blue, green, and red in roughly 400-700 nanometers. But that spectrum can then be depth-adjusted from 8-40 meters seawater depth where you will see the effect that the water has on light spectrum penetration as it filters out first the red, then the orange, yellow, and green, as the simulation sinks to 40 meters.
This is of course a bit of a gimmick as most reefers can simulate depth via channel control anyway, adjusting down the red, green, and amber channels while pushing Royal blue to the max. But for a light in this price bracket, the app certainly is feature-rich. It shows operating temperature too.
The three model sizes are populated with 24, 48, and 72 diodes in total and run at a maximum of 20, 40, and 60 watts respectively. This, and the lack of lenses, does limit light punch somewhat with peak par just over 160 at 6” water depth and when you go past 12” depth it drops to well below 100.
The four-inch width of the unit and narrower still where the LEDs are situated means that if used as the sole form of lighting, you would need the tank to be just a foot deep and a foot wide (like a 20 gallon long,) in order to grow most corals. And if you wanted to light wider or deeper tanks multiple units would be required.
HM Electronics
The lights are super slim at two-thirds of an inch thick, and lightweight too, with even the 36” length unit weighing in at just three and a half pounds. Visit the app and it looks like the Grassy Wing is manufactured by HM Electronics in Taiwan – a company that is no stranger to global reef tank lighting. And there on the HM website is a very similar light, also named Wing, only with a sturdier mounting solution and slightly different wattages.
Grassy Wing2 is also available in a freshwater model to serve the sizable aquascaping fraternity in Japan and with a similar form factor to the myriad RGB, (ADA Aquasky style,) lights on offer over there. For Wing 2 Fresh, depth spectrum control becomes color temperature settings in Kelvin instead.
Pricing converts to around $164, $231, and $328 for the three Wing2 Marine 30, 60, and 90 models.
