Summary #

GHL’s Mitras illumination family covers two different fixture types for aquarium lighting: Mitras Lightbar and Mitras Slimline, linear bar fixtures for open, closed, or canopied aquariums, and the Mitras LX fixtures, a pendant luminaire for open aquariums with its own onboard controller. This article compares the product lines by channel count, form factor, and control options, and explains two concepts that come up across the lineup: how lumen, lux, and PAR relate to photosynthesis, and how GHL’s Power Balancing Technology works on the models that support it.

Applies to #

• Mitras Lightbar 1-3
• Mitras Slimline
• Mitras LX6 Series
• Mitras LX7 Series (incl. Industrial Line / IL)
• Mitras LX8 Series

Overview #

The right Mitras fixture depends mainly on the aquarium’s setup — open vs. closed or canopied — and on how many independently dimmable color channels the application needs.

Lightbar & Slimline — bar fixtures #

Bar fixtures mounted in or above the aquarium, for use in closed or canopied tanks as well as open ones. Without a ProfiLux, they run at a fixed 100% and can only be switched on/off by a simple timer — dimming, spectrum mixing, and all simulations require a ProfiLux connection via the Mitras LB port.

• Mitras Slimline: 2 color channels per fixture (5-7 channels total with the optional Mitras Slimline RGB add-on), with pre-mixed color temperatures per model rather than individually tunable LED colors.
• Mitras Lightbar 2: 5 channels (Daylight model) or 7 channels (Ocean Blue, Actinic, Deep Actinic).
• Mitras Lightbar 3: 7 channels across all five spectrum variants (Coral Pop, Deep Ocean, Ocean Blue, Skywhite, Refugium), with GHL’s Total Reflection and Diffusion Technology (TRDT™) for more uniform color mixing than Lightbar 2.

For installation and wiring, see Mitras Lightbar & Slimline – Setup Guide.

Mitras LX — pendant fixture #

A standalone luminaire with its own onboard controller, WiFi, and USB — for open aquariums only (minimum 20cm/7.9″ clearance to the water surface; not for use under a cover). Unlike Lightbar and Slimline, the Mitras LX can hold and run a full lighting schedule entirely on its own, or synchronize multiple units in Master/Slave mode, with or without a ProfiLux.

• Mitras LX8: 10-12 independently dimmable color channels plus 1 dedicated moonlight channel, in three spectrum variants (Freshwater, Marine, Coral Pop). A 6-cluster model plus the separate moonlight cluster, up to 250W.
• Mitras LX7: 9 independently dimmable color channels, available in four spectrum variants (Freshwater, Marine Water, Coral Pop, Aquaculture). Two size classes: LX7x04 (4 LED clusters, up to 131W) and LX7x06 (6 LED clusters, up to 195W).

For installation and wiring, see Mitras LX6 & LX7 – Setup Guide.

How it works #

Lumen, lux, and PAR #

Lumen and lux are commonly used to compare or size lighting fixtures — for example in lumens-per-liter rules of thumb — but these values are only meaningful for daylight-weighted spectra. For blue-heavy marine spectra (Actinic, Ocean Blue, Coral Pop, Deep Ocean, and similar), lumen and lux systematically understate the actual light output, since they are weighted to human eye sensitivity rather than photosynthetic value.

• Lumen: Total visible light output, weighted to human eye sensitivity, which peaks in green and falls off toward blue and red.
• Lux: Lumen per unit area — how bright a surface appears to the eye — and inherits the same spectral bias as lumen.
• PAR (Photosynthetically Active Radiation): Light output only in the 400-700nm range that drives photosynthesis, independent of how the human eye perceives it — the more meaningful figure for comparing fixtures by growth potential rather than perceived brightness.

Because of this bias, a blue-heavy spectrum will always show a lower lumen figure than a Daylight spectrum at the same electrical power, even though those blue wavelengths are among the most efficient for photosynthesis. For sizing or comparing blue-heavy spectra, electrical power (W) is a more reliable reference than lumen or lux — see the wattage-per-liter guidance on the respective product page. PAR is the most direct measure of photosynthetic light, but PAR readings themselves vary with the meter, sensor calibration, and measurement distance used, so values from different sources or manufacturers are not always directly comparable.

Power Balancing Technology (PBT / PBF) #

On fixtures with multiple independently dimmable color channels, reducing one channel’s output normally reduces the fixture’s total light output too — the unused power simply goes unused. GHL’s Power Balancing Technology redistributes that saved power to the remaining channels instead, so the fixture keeps operating near its maximum total output even when the color mix shifts heavily toward certain channels.

• Example: a 100W fixture with four 25W channels (red, green, blue, white) reaches 100W of total output only when every channel runs at 100%.
• Without Power Balancing: reducing red and green to 10W each leaves 30W of the fixture’s capacity unused (70W total output).
• With Power Balancing: that spare 30W is redistributed across blue and white instead, so the fixture still outputs its full 100W even with red and green significantly reduced.

Mitras Lightbar 1 & 2 and the Mitras LX7 expose this as a per-channel Power Balancing Factor (PBF) — see the respective Setup Guide for where to configure it.

System Requirements #

Beyond the fixture itself, the required accessories depend on the level of control:

• Undimmed / standalone operation (Lightbar or Slimline): Power supply and a Splitter — no controller needed. All channels run at a fixed 100%, switched by a simple external timer.
• ProfiLux-controlled Lightbar or Slimline: A Mitras LB Splitter (Lightbar) or Slimline Splitter dimmable (Slimline), connected to the Mitras LB port on a ProfiLux or Expansion Box 2. More than 4 Lightbars require an ActiveSplitter.
• ProfiLux-controlled LX: A PLM-PWC expansion card in the ProfiLux, communicating wirelessly with the LX’s onboard RF module.
• Standalone or Master/Slave LX (no ProfiLux): WiFi or USB for initial configuration via GHL Connect or GHL Control Center — no expansion card needed.

Choosing the right Mitras fixture #

Open display tank, maximum control #

A ProfiLux-controlled Mitras LX offers the most channels (8-13) and full simulation control, and can be matched with a Coral Pop or Marine Water spectrum for reef tanks.

Closed or canopied tank #

Mitras Lightbar and Slimline are the only Mitras fixtures rated for use inside a canopy or closed hood — the LX7 requires open air above the water and cannot be used under a cover.

Simpler, lower-cost spectrum control #

Mitras Slimline uses fewer, pre-mixed color channels (2 per fixture) compared to Lightbar’s 5-7, trading fine spectral control for a lower cost — a good fit when broad color adjustment is enough.

Refugium or macroalgae section #

The Mitras Lightbar 3 Refugium spectrum is purpose-built for macroalgae and microorganism growth at low energy consumption.

Budget-conscious or expanding setups #

Both Lightbar and Slimline can run undimmed on a simple timer with no controller, and be upgraded to full ProfiLux control later without replacing the fixture — only the Splitter and cabling change.