PHOTOBIO CX 2125 LED 850W 100/277V S4 (10′ Leads Cord)

The PHOTOBIO CX 2125 LED is an 850W full-spectrum top-light fixture rated at 2125 umol/s photon flux at 277V, designed as a direct 1:1 replacement for 1000W DE HPS fixtures. It ships with a 10-foot bare wire leads power cord, a 10-foot PHOTO•LOC 0-10V control cable, and mounting C clamps — ready for commercial grow rooms and vertical-stacking operations.

PHOTOBIO CX 2125 LED Specifications

All specifications are sourced from the manufacturer product listing. Photon flux values are measured at 277V input.

Specification	Value
Power Draw	850W
Input Voltage	120–277V (universal)
Photon Flux (PPF)	2125 umol/s @ 277V / 2087 umol/s
Photon Efficacy	2.5 umol/J
Spectrum	S4 Full Spectrum (Osram/Seoul diodes)
Dimensions (L x W x H)	24.1 x 14.2 x 2.6 inches
Weight	22.7 lbs (22.7204 lbs)
IP Rating	IP66
Dimming / Control	iLOC push-button + 0-10V (PHOTO•LOC cable included)
Controller Compatibility	Autopilot PX Controllers (up to 500 fixtures per zone)
Cooling	Passive (heat-dissipating fins, fanless)
In the Box	Fixture, 10' bare-wire leads cord, 10' PHOTO•LOC 0-10V cable, C clamps
Warranty	5 years
SKU	PTB8850LS47

Why Choose the PHOTOBIO CX 2125 LED

The CX 2125 sits at the top of the PHOTOBIO lineup for single-fixture photon output. Here is what distinguishes it from other 850W-class LEDs and from the 1000W DE HPS fixtures it replaces:

• Highest photon output in the PHOTOBIO lineup. At 2125 umol/s photon flux (277V) and 2.5 umol/J efficacy, the CX 2125 delivers more photons per watt than older HPS technology at the same or lower energy draw. The 2087 umol/s PPF rating is the measured output figure growers use to calculate canopy PPFD.
• S4 full spectrum with Osram and Seoul diodes. The S4 spectrum emphasizes red, far-red, and blue wavelengths. This diode mix supports both vegetative development and flowering without spectrum-switching hardware. Osram and Seoul diodes are commercial-grade components specified for long-run stability.
• 2.6-inch slim profile for vertical real estate. At 2.6 inches tall, the CX 2125 occupies minimal vertical clearance. In multilayer or low-ceiling rooms where every inch matters, this is a practical advantage over taller fixture housings. The 24.1 x 14.2 inch footprint is sized to cover a 1000W DE-equivalent zone.
• Passive cooling — no moving parts. Heat-dissipating aluminum fins remove heat without fans. No fans means no fan noise, no fan failures, and no additional airflow management required for the fixture itself. This also simplifies long-term maintenance.
• iLOC on-board dimming with 0-10V compatibility. The iLOC push-button interface lets the grower step output up or down based on crop stage without purchasing a separate controller. The included 10-foot PHOTO•LOC 0-10V cable also enables integration with Autopilot PX Controllers, supporting zone-level dimming across up to 500 fixtures simultaneously.
• IP66 ingress protection. IP66 is suitable for humid greenhouse environments and washdown-compatible grow rooms. Moisture and particulate ingress are addressed by the enclosure rating.

Best Uses for the PHOTOBIO CX 2125 LED

This fixture is built for professional and commercial horticultural production. The following use cases match the product’s rated output, footprint, and control features:

• 1:1 replacement of 1000W DE HPS fixtures. The CX 2125 is explicitly rated as a direct drop-in replacement for 1000W double-ended HPS. Growers converting existing HPS rooms can swap fixtures into existing hangers and wiring without redesigning the layout. The similar footprint means PPFD maps are comparable between old and new installations.
• Commercial flower rooms (high-PPFD crops). At over 2000 umol/s PPF, this fixture delivers intensity levels required for fruiting and flowering crops — cannabis, tomatoes, peppers, and cucumbers — where canopy PPFD targets typically run 800–1200 umol/m²/s or higher in supplemental or sole-source setups.
• Rooms requiring zone-level dimming control. The Autopilot PX Controller integration (up to 500 fixtures per zone) makes the CX 2125 appropriate for facilities where multiple zones are managed centrally. The iLOC on-board control also allows manual output adjustment per fixture for non-automated spaces.
• Humid and high-washdown environments. The IP66 rating makes this fixture suitable for greenhouse bays, nutrient-fogger rooms, and grow spaces that require regular cleaning with water. Fixtures without sealed enclosures are not suitable for these environments.
• Tight-ceiling grow rooms and vertical farms. The 2.6-inch vertical profile allows installation in spaces where ceiling clearance is limited, and in multilayer rack systems where fixture height directly competes with plant canopy height.

PHOTOBIO CX 2125 LED vs 1000W DE HPS Fixtures

The canonical comparison for this fixture — as stated in the manufacturer’s own documentation — is against 1000W double-ended HPS fixtures. The table below summarizes the key differences based on published specifications:

Factor	PHOTOBIO CX 2125 LED (850W)	Typical 1000W DE HPS
Power draw	850W	~1050W (ballast + lamp)
Photon flux	2087–2125 umol/s PPF	Typically 1600–1900 umol/s
Efficacy	2.5 umol/J	~1.5–1.8 umol/J typical
Spectrum	S4 full spectrum (tunable far-red, red, blue)	Fixed HPS spectrum (yellow/orange dominant)
Cooling	Passive fins (fanless)	Radiant heat — requires HVAC offloading
Profile height	2.6 inches	Reflector housing typically 8–14 inches
IP rating	IP66	Varies — typically IP54 or lower
Lamp replacement	No consumable lamp	Lamp replacement required every 10,000–18,000 hours

The efficiency and photon output advantage is consistent with the direction of LED versus HPS technology across the industry. HPS fixtures remain relevant where upfront cost is the primary constraint. The CX 2125’s 1:1 footprint compatibility allows a staged room conversion without reworking hanging infrastructure. If you are also considering other high-output LED fixtures, see the Gavita Pro 1700e LED for a comparison point at a different form factor and output level.

Compatibility & Operating Range

The PHOTOBIO CX 2125 is designed for broad facility compatibility:

• Input voltage: 120–277V universal input. This covers standard North American 120V single-phase circuits, 208V and 240V circuits common in commercial facilities, and 277V from commercial 480V three-phase panel legs. No separate voltage-select switch is required — the driver auto-ranges.
• Controller compatibility: Integrates with Autopilot PX Controllers via the included 10-foot PHOTO•LOC 0-10V cable. Up to 500 fixtures can be managed per zone. The iLOC on-board interface provides manual dimming without a controller.
• Environmental rating: IP66 — protected against powerful water jets and total dust ingress. Suitable for greenhouse and commercial grow room environments with high humidity and regular washdowns.
• Power cord: This variant ships with a 10-foot bare wire leads cord. Bare wire leads are intended for direct hardwiring into a junction box or panel circuit. Growers requiring a NEMA plug (L7-15P or 6-20P) should select the corresponding cord variant.
• Mounting: C clamps are included for standard fixture hanging bars and light rails.

For growers building out a full controlled environment, the Advance Grow Tent System 4×4 is an example of an enclosed structure that can house this fixture in smaller-scale deployments. In commercial settings, the CX 2125 pairs with dedicated grow room framing and HVAC rated for the heat load of the installed fixture count.

Usage Guidelines

Lighting output should be matched to crop species, growth stage, and mounting height. The following guidelines are derived from the fixture’s photon flux rating and standard commercial practice:

• Canopy PPFD targets by stage: Vegetative crops typically target 400–600 umol/m²/s. Flowering and fruiting crops (cannabis, tomatoes) typically target 800–1200 umol/m²/s at canopy. At 2087 umol/s PPF, the CX 2125 can achieve these targets over a coverage area appropriate to the 1000W DE footprint it replaces.
• Mounting height: Higher mounting increases coverage area but reduces PPFD at canopy. Lower mounting increases intensity but risks hotspots at the center of the coverage zone. Use a quantum PAR meter to verify PPFD uniformity at canopy level before locking in hanging height.
• iLOC dimming: Use the iLOC push-button interface to reduce output during propagation or early vegetative stages. The 0-10V PHOTO•LOC input allows ramp-up and ramp-down scheduling when connected to an Autopilot PX Controller.
• Photoperiod: LED fixtures do not emit significant UV or infrared compared to HPS. Photoperiod scheduling (hours on/off) follows the same principles as HPS — 18/6 for vegetative, 12/12 for flowering in photoperiod-sensitive crops.
• Heat management: The passive cooling design dissipates heat through the aluminum fins. Ensure adequate airflow across the top of the fixture housing. Do not install in fully enclosed spaces without any air exchange — the fins require ambient airflow to transfer heat away from the driver and diode array.

How to Install the PHOTOBIO CX 2125 LED

The fixture ships with C clamps, a bare wire leads power cord, and a PHOTO•LOC 0-10V control cable. Installation involves three sub-tasks: mechanical mounting, electrical connection, and control wiring.

1. Plan the layout and de-energize the circuit. Confirm that the circuit breaker feeding the grow room is off before any wiring work. Verify the circuit is rated for the fixture’s draw (850W at the operating voltage being used).
2. Mount the fixture. Attach the included C clamps to the fixture’s hanging points and hang the fixture from a light rail, ratchet hanger, or overhead bar at the planned mounting height. Ensure the fixture is level and the hangers can support the 22.7 lb load.
3. Connect the bare wire leads power cord. The bare wire leads variant requires hardwiring into a junction box or directly to a circuit. Strip the leads to the appropriate length and connect Line (black/red), Neutral (white/grey), and Ground (green/bare) per your local electrical code. If you are not a licensed electrician and local code requires a permit, engage a licensed contractor for this step.
4. Route and connect the PHOTO•LOC control cable (if using a controller). Plug one end of the 10-foot 0-10V PHOTO•LOC cable into the fixture’s control port and route the cable to your Autopilot PX Controller or compatible 0-10V dimming controller. Connect per the controller’s wiring diagram. If dimming control is not needed, the iLOC push-button interface can be used without the control cable connected.
5. Re-energize and verify operation. Turn the circuit breaker back on. The fixture should illuminate. Check the iLOC digital screen to confirm output level. If connected to a controller, verify the controller is reading the fixture and dimming commands are registering correctly.
6. Set mounting height and measure PPFD. Use a quantum PAR meter at multiple canopy points to confirm PPFD uniformity. Adjust mounting height as needed. Document the height, PPFD readings, and photoperiod schedule for the facility log.

For propagation setups with lower light requirements, see the Super Sprouter Premium Heated Propagation Kit with T5 light — a compact, low-intensity starter option before transplants move under the CX 2125.

Sources & Further Reading