According to published technical documentation from Heliospectra MITRA X FLEX Technical Documentation (2025), the FLEX architecture is defined by its ability to deliver three distinct operating modes within a single fixture footprint. Understanding how these three modes operate is essential for engineering a project-specific alternative
Broad Spectrum Mode (PAR Only)
In Broad Spectrum mode, the fixture operates as a standard high-efficiency greenhouse top light, emitting photons exclusively within the traditional Photosynthetically Active Radiation (PAR) waveband (400–700 nm).
When developing an alternative for this mode, technical evaluation must compare:
- Complete broad-spectrum SPD: Spectral Power Distribution across blue (400–500 nm), green (500–600 nm), and deep red (600–700 nm).
- PAR photon output: Total Photosynthetic Photon Flux (PPF in µmol/s) delivered exclusively between 400 nm and 700 nm.
- Red, blue and green distribution: Relative energy percentages (e.g., R40 vs R80 spectrum variants) to maintain consistent vegetative drive.
- Input power: Active AC electrical wattage consumed when far-red channels are completely powered down.
- Fixture intensity: Maximum micro-mole output per fixture at full PAR load.
- Greenhouse PPFD distribution: Floor-level Photosynthetic Photon Flux Density (PPFD) uniformity across the canopy.
Broad Spectrum + Far-Red Mode (Extended PAR / ePPF)
Broad Spectrum + Far-Red mode activates both the primary broad-spectrum LEDs and the auxiliary far-red diodes simultaneously. This mode delivers an extended photon spectrum (400–800 nm), commonly evaluated under extended Photosynthetic Photon Flux (ePPF) standards.
When developing an alternative for this combined mode, technical evaluation must compare:
- Combined SPD: Total spectral emissions bridging PAR and far-red wavebands.
- PAR and far-red photon output: Disaggregated photon flux accounting for both 400–700 nm PPF and 700–800 nm Far-Red Photon Flux (PFD_FR).
- Red-to-far-red ratio: The phytochrome-active R:FR photon ratio (660 nm to 730 nm ratio), which regulates plant shade avoidance responses.
- ePPF or extended photon output: Total photon emissions across 400–800 nm (ePPF in µmol/s).
- Total input power: Maximum AC power draw when all LED arrays operate at full capacity.
- Spectral stability during switching: Verification that primary broad-spectrum PPF output remains completely stable (does not drop or thermal-throttle) when the far-red channel is toggled ON.
Far-Red-Only Mode (Targeted Treatment)
Far-Red-Only mode completely shuts down the main white and deep-red PAR LEDs, powering only the far-red LED array (700–800 nm). This mode is utilized primarily for short-duration End-of-Day (EOD) lighting pulses or end-of-production height adjustments.
When developing an alternative for far-red-only mode, technical evaluation must compare:
- Far-red peak wavelength: Central dominant emission wavelength (typically 730 nm or 735 nm).
- Spectral bandwidth: Full Width at Half Maximum (FWHM) of the far-red LED emissions (typically 25–35 nm).
- Far-red photon output: Dedicated PFD_FR output (µmol/s) delivered during far-red-only operation.
- Beam distribution: Optical lens beam angles ensuring far-red photons spread evenly across the canopy during low-intensity treatments.
- Mode-specific input power: Power draw during far-red-only operation, which is significantly lower than main broad-spectrum operation.
- Minimum and maximum controllable intensity: Dimming range and resolution when adjusting far-red treatment intensity.
- Scheduling and shutoff behavior: Precision timer execution to guarantee instant, clean shutoff after timed treatments without residual glow.
Architecture Clarification: Having three spectral modes does not automatically imply three fully independent, multi-channel dynamic dimming channels. The original MITRA X FLEX platform is best defined as a switchable or semi-flexible far-red platform, designed to toggle or mix far-red with broad white/red light. It should not be confused with fully dynamic multi-channel architectures (such as C3 or C4 platforms) where blue, red, white, and far-red channels are individually addressable from 0% to 100%.
FY LIGHTING Far-Red Grow Light Options
Because commercial greenhouse projects vary in layout, driver placement, and control infrastructure, FY LIGHTING offers three distinct custom engineering routes when developing a project-specific MITRA X FLEX alternative. If a customer’s requested fixture is not an in-stock catalog item, FY LIGHTING presents it as a custom-developed alternative tailored to project requirements.
FY LIGHTING CUSTOM DEVELOPMENT ROUTES Option 1: Integrated Broad-Spectrum & Far-Red Fixture
- Single physical housing with internal dual-channel driver logic
- Toggles Broad, Broad+FR, and FR-Only via external control signal Option 2: Broad-Spectrum Top Light + Modular Far-Red Light Bar
- Primary high-power broad-spectrum fixture (e.g., 600W-1000W)
- Independent, clip-on or rack-mounted 730nm/735nm far-red bar Option 3: Pre-Configured Four-Channel Platform (FLEX Emulation)
- Built on FY LIGHTING’s 4-channel hardware platform
- Preset control firmware locked to emulate FLEX 3-mode operation
Option 1: Integrated Broad-Spectrum and Far-Red Fixture
In this configuration, white, red, and far-red LED arrays are housed within a single physical fixture extrusion, powered by an integrated dual-channel driver. Mode switching is managed via an internal control circuit triggered by 0–10V, PWM, RS485, or wireless commands.
- Advantages: Direct 1-for-1 form-factor replacement; single power drop per fixture location; minimal installation labor.
- Best Suited For: Retrofit projects replacing installed FLEX fixtures without altering existing mounting brackets or electrical drops.
Option 2: Broad-Spectrum Fixture with a Separate Far-Red Module
This modular approach pairs a high-efficiency broad-spectrum top light fixture with an independent, slimline far-red light bar mounted adjacent to or underneath the main fixture.
- Advantages: Complete physical separation of PAR and Far-Red thermal loads; far-red bars can be switched off or repositioned independently; lower cost if far-red treatments are only required in select greenhouse zones.
- Best Suited For: Greenhouses conducting targeted End-of-Day (EOD) treatments where far-red is only activated for 15–30 minutes daily.
Option 3: Four-Channel Platform Configured for FLEX Operation
Utilizing FY LIGHTING’s multi-channel LED hardware, the driver logic is pre-programmed to restrict operation to three locked spectral recipes that match the FLEX operational profile:
- Recipe A: Broad-spectrum white + deep red (100% PAR / 0% FR).
- Recipe B: Broad-spectrum + far-red (100% PAR / 100% FR).
- Recipe C: Far-red only (0% PAR / 100% FR).
- Advantages: Superior long-term flexibility; allows future upgrade to full multi-channel dynamic spectrum control if crop requirements change.
- Best Suited For: Research facilities or high-value crop operations anticipating future light recipe adjustments.
Custom Engineering Deliverables Provided During Validation
When developing a project-specific alternative, FY LIGHTING provides complete engineering documentation prior to mass production:
- Proposed fixture 3D rendering and engineering prototype samples.
- Integrating sphere test reports for Broad-Spectrum SPD, Far-Red-Only SPD, and Combined SPD.
- Mode-switching logic circuit diagrams and driver wiring schematics.
- High-resolution photographs of far-red LED module assemblies.
- Mechanical dimensional drawings highlighting mounting bracket placement and glass clearance.
- Control interface documentation for 0–10V, Modbus, and climate computer integration.
Strict Terminology Standard: To maintain complete commercial transparency, proposed solutions are formally designated as custom-developed MITRA X FLEX alternatives, project-specific far-red replacement solutions, or custom far-red greenhouse fixtures. FY LIGHTING does not market unvalidated custom products as “in-stock replacements,” “direct drop-in fixtures,” or “proven one-for-one equivalents” until sample testing and pilot zone validation are complete.
Matching Far-Red Wavelength and Spectrum
A successful far-red replacement requires precise spectral matching. Simply adding “far-red LEDs” to a fixture is insufficient; the spectral power distribution (SPD) must be calibrated to match the target photobiological response.
Photo-Equilibrium | Phytochrome Pfr / Ptotal steady-state equilibrium
FAR-RED SPECTRAL PARAMETERS TO MATCH Peak Wavelength | 730nm vs 735nm nominal diode center Bandwidth (FWHM) | 25nm to 35nm spectral spread Photon Flux (PFD) | Far-red micromoles per second (700-800nm) R:FR Ratio | 660nm Red to 730nm Far-Red ratio
When matching far-red performance, FY LIGHTING engineering evaluates:
- Peak Wavelength: Ensuring diode center wavelengths line up with phytochrome absorption peaks (730–735 nm).
- Full Width at Half Maximum (FWHM): Verifying the spectral spread of the far-red LED emissions to avoid unintended infrared thermal bleed (>800 nm).
- Far-Red Photon Flux (PFD_FR): Quantifying actual far-red micromoles delivered per second (µmol/s in 700–800 nm).
- Red-to-Far-Red (R:FR) Ratio: Calibrating the ratio between 660 nm red and 730 nm far-red photons to control stem elongation and canopy architecture.
- Phytochrome Photo-Equilibrium (Pfr/Ptotal): Calculating the estimated phytochrome photostationary state (P fr/P total) established under each operating mode.
- Dimming Stability: Ensuring far-red spectral output ratio does not shift significantly when dimmed from 100% down to 10%.
- Thermal Spectral Drift: Verifying that LED junction temperature increases during continuous operation do not shift peak far-red emissions beyond acceptable tolerances (typically <3 nm drift at 80°C junction temperature).
Does a MITRA X FLEX Alternative Need a 735nm LED Grow Light?
A common question among facility growers is whether a FLEX replacement must specifically utilize 735 nm LEDs.
- Public Documentation Scope: Public technical datasheets for the MITRA X FLEX platform specify far-red inclusion but do not explicitly disclose the exact nominal diode peak wavelength. However, related Heliospectra adjustable platforms (such as ELIXIA) list 735 nm far-red LED channels.
- Diode Specification Realities: Commercial horticultural LED manufacturers (such as Osram, Lumileds, or Samsung) classify far-red diodes across nominal peak bands ranging from 720 nm to 740 nm, with 730 nm and 735 nm being the most prevalent.
- Spectral Bandwidth Overlap: A 730 nm LED and a 735 nm LED exhibit significant spectral overlap due to their 30 nm FWHM emissions curve. Both effectively drive phytochrome conversion (P fr → Pᵣ).
- Project-Specific Selection: Nominal diode wavelength alone does not dictate photobiological efficacy. The complete emitted SPD and total far-red photon flux density (PFD_FR) must be measured using a calibrated spectroradiometer.
FY LIGHTING Capability: FY LIGHTING, an experienced far-red grow light manufacturer, can develop an adjustable far-red grow light and 735nm LED grow light configuration for greenhouse morphology lighting based on the project’s required SPD, output, and treatment schedule. Diode selection is finalized after analyzing the original fixture’s spectral data or client-provided spectrometer measurements.
Far-Red Mode Switching, Dimming, and End-of-Day Treatments
Mode Switching & Dimming Control Protocols
Achieving reliable far-red operation requires robust control signal integration between the fixture driver and the greenhouse climate control computer.
MODE SWITCHING & CONTROL SIGNALS Signal Type | Mode 1 (Broad) | Mode 2 (Broad+FR) | Mode 3 (FR) Dual 0-10V Channel | Ch1: 10V / Ch2: 0V | Ch1: 10V / Ch2: 10V | Ch1: 0V / Ch2: 10V RS485 / Modbus | Register 0x01 | Register 0x02 | Register 0x03 PWM Control | Duty A: 100% | Duty A & B: 100% | Duty B: 100%
When evaluating a custom replacement system, the control architecture must be validated across:
- Mode-Switching Reliability: Clean transitions between Broad, Broad+FR, and FR-only modes without signal latency or relay chatter.
- Independent Channel Adjustment: Verifying whether broad-spectrum PAR and far-red intensity can be dimmed independently or if they follow preset ratio steps.
- Minimum Stable Output: Confirming far-red LED arrays remain stable at low dimming levels (e.g., 5–10% output) without flickering.
- Transition Latency: Instantaneous channel response (<1 second) during automated End-of-Day triggers.
- Schedule Recall & Power Loss Memory: Ensuring internal driver memory retains mode schedules following greenhouse mains power interruptions.
- Fail-Safe Shutoff Protocols: Automatic far-red channel shutdown if communication signals are lost, preventing unintended continuous far-red exposure during dark photoperiods.
Control Testing Rule: Avoid claiming “fully independent 0–100% dimming of both channels” unless physical driver tests have verified independent dual-channel analog or digital signal response. In engineering proposals, express this as: “The proposed replacement can be configured and tested for the required mode switching and far-red intensity control.”
End-of-Day Far-Red Lighting (EOD) Treatment Protocols
End-of-day far-red lighting treatment is one of the primary operational modes utilized by commercial greenhouse growers. By exposing crops to a brief pulse of far-red light at the end of the daily photoperiod (or immediately into the dark period), growers manipulate phytochrome photo-equilibrium.
TYPICAL END-OF-DAY (EOD) LIGHTING SCHEDULE 06:00 – 22:00 (16 Hours) | Main Photoperiod (Broad Spectrum Mode) 22:00 – 22:30 (30 Minutes) | EOD Far-Red Treatment (Far-Red Only Mode) 22:30 – 06:00 (7.5 Hours) | Dark Period (Complete Light Shutoff)
Physiological mechanisms driven by EOD far-red include:
- Phytochrome Reset: Converts active P fr (phytochrome far-red) into inactive Pᵣ (phytochrome red), simulating natural twilight and signaling immediate dark-period entry to the plant circadian clock.
- Stem & Petiole Elongation: Triggers controlled cell elongation, expanding canopy architecture to improve sunlight interception in dense greenhouse plantings.
- Flowering & Morphological Acceleration: Accelerates flower initiation in short-day plant species or promotes broader leaf surface area in leafy greens and fruiting vegetables.
According to peer-reviewed horticultural research published in Frontiers in Plant Science Tomato Far-Red Study (2019), EOD far-red treatments significantly influence tomato stem height and canopy light distribution. However, the study demonstrated that plant responses vary dramatically depending on treatment duration, background PAR intensity, and cultivar genetics.
KEY PARAMETERS FOR EOD TREATMENT DESIGN Treatment Timing | Start time relative to main photoperiod shutoff Treatment Duration | Typically 15 to 30 minutes (up to 60 min max) Far-Red Flux (PFD) | Applied photon density (typically 10-50 umol/m²/s) Background DLI | Natural sunlight + supplemental daily light integral Temperature Regime | Greenhouse day/night DIF (temperature differential)
Commercial Treatment Recommendation: End-of-day far-red settings should be developed around the crop, cultivar, treatment objective, and greenhouse environment, then validated in a pilot area before full deployment. Never apply a blanket “15-minute” or “30-minute” recipe across all crops without preliminary trial validation.
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