Titan Controls Spartan Series CO2 Monitor

The Titan Controls Spartan Series CO2 Monitor (SKU HGC702026) is a compact, USB-powered display that tracks CO2 concentration and ambient temperature in indoor grow rooms and greenhouses. A dual-beam NDIR sensor reads CO2 levels up to 3,000 ppm, and a large screen makes it easy to confirm the current concentration at a glance. The unit is the monitor-only variant in Titan Controls’ Spartan Series — for growers who need an accurate readout without active dosing control.

Titan Controls Spartan Series CO2 Monitor Specifications

The Spartan Series CO2 Monitor uses a dual-beam non-dispersive infrared (NDIR) sensor to read carbon dioxide concentration in parts per million. It runs from a standard USB power supply included in the box and is designed for indoor grow-room environments. The table below summarises the published specifications gathered from the brand site and authorised retailer listings.

Specification	Value
Model / SKU	HGC702026
Brand	Titan Controls (Hawthorne Gardening Company)
Function	CO2 and ambient temperature monitor (display only, no setpoint control)
CO2 Sensor	Dual-Beam NDIR (Non-Dispersive Infrared)
CO2 Range	Up to 3,000 ppm
Temperature Monitoring	Yes — simultaneous CO2 + ambient temperature
Display	Large readout screen for quick visual confirmation
Photocell	Built-in (relevant on controller variant for daytime-only dosing)
Power Supply	USB power adapter (included)
Voltage / Frequency	120 V / 60 Hz
Max Amperage	15 Amps maximum (series rating)
Housing	Dust and moisture-resistant plastic
Dimensions	9.6 in x 6 in x 2.4 in
Weight	0.798 lb
Warranty	1 year (per Spartan Series listings)
Intended Use	Indoor grow rooms, greenhouses, sealed cultivation spaces

Why Choose the Titan Controls Spartan Series CO2 Monitor

Titan Controls describes the Spartan Series as “streamlined, single-function controllers for growers who prefer dedicated devices for each environmental variable.” The CO2 Monitor (HGC702026) is the simplest device in that lineup — it reads CO2 and temperature, and that is all it does. Several details set it apart from generic CO2 meters or full-feature environmental controllers.

• Dual-Beam NDIR sensor. Non-dispersive infrared sensors measure CO2 by detecting how much infrared light a sample of air absorbs at the CO2 absorption wavelength. The dual-beam configuration uses a second reference beam to compensate for sensor drift over time, which improves reading stability across the life of the unit. NDIR is the same technology used in industrial and HVAC-grade CO2 instruments.
• 3,000 ppm measurement range. The 3,000 ppm ceiling covers the full range of CO2 levels relevant to indoor horticulture. Ambient outdoor CO2 sits near 420 ppm; supplemented grow rooms typically run between 800 and 1,500 ppm during lights-on, and the upper portion of the range is available for high-light, high-canopy cultivars that respond to elevated CO2.
• Large display screen. The monitor uses a single large readout rather than a multi-line menu interface. Growers can confirm the current CO2 concentration with a glance from across the room, which is the primary day-to-day task for a monitor in a working cultivation space.
• USB power. The unit ships with a USB power adapter and runs on 120 V / 60 Hz house power. It does not require a dedicated outlet for a controller and can be relocated easily as a room is reconfigured.
• Simultaneous CO2 + temperature. A single device tracks the two variables that drive plant respiration: carbon dioxide concentration and ambient air temperature. CO2 uptake by plants is strongly temperature-dependent — high CO2 with low canopy temperature delivers diminishing returns — so seeing both values on one screen helps growers diagnose stalled growth without cross-referencing separate instruments.
• Single-purpose, lower price point. Within the Titan Controls range, the Spartan Monitor sits well below the Atlas series controllers, which add fuzzy-logic dosing control, remote sensors, and day/night setpoints. For growers who do not need automated CO2 dosing, the monitor delivers the read-only function without paying for control circuitry.
• Dust and moisture-resistant enclosure. The plastic housing is rated to resist the elevated humidity and airborne particulate common in indoor grow rooms, extending useful life compared to consumer-grade air-quality meters not built for these conditions.

Best Uses for the Titan Controls Spartan Series CO2 Monitor

The Spartan Monitor is most useful in cultivation environments where a grower already controls CO2 dosing manually or via a separate regulator/controller and needs a reliable, dedicated readout to verify levels. The applications below match the product’s specifications and intended deployment context.

• Verifying CO2 dosing in supplemented grow rooms. Growers who run a CO2 generator or tank/regulator system on a timer often need a second device to confirm the resulting ppm level inside the canopy. The Spartan Monitor sits in the room and displays the real-time concentration, letting the grower confirm the dosing program is hitting the target band of roughly 800–1,500 ppm during lights-on.
• Spot-checking sealed cultivation rooms. Sealed grow rooms accumulate CO2 from natural plant respiration during lights-off and may build up to elevated levels if the space is not well-vented before personnel enter. A wall-mounted monitor gives an immediate read on whether the room is safe to enter and work in.
• Greenhouse CO2 readouts. In greenhouses where CO2 supplementation runs only during certain hours or under specific light conditions, the monitor provides on-site verification that the supplementation system is reaching the canopy zone rather than escaping through vents or settling at floor level. Pair it with an oscillating circulation fan to keep CO2 mixed evenly through the canopy.
• Diagnosing slow growth in unsupplemented spaces. In rooms without active CO2 dosing, ambient CO2 can deplete during lights-on as plants pull carbon out of the air faster than infiltration replaces it. A monitor confirms whether ambient CO2 is dropping below the ~400 ppm baseline, which indicates the room needs more passive ventilation or supplementation to recover photosynthetic rates.
• Calibration verification for an existing controller. Growers running a separate CO2 controller (such as a Titan Controls Atlas or a competing brand) can use the Spartan Monitor as a second independent reading to verify the controller’s onboard sensor has not drifted. If the two devices disagree by more than the expected sensor tolerance, the controller’s sensor may need cleaning or replacement.
• Personnel safety in CO2-enriched spaces. Indoor cultivation operations using CO2 generators or tanks should have at least one independent monitor displaying current ppm so workers entering the space can confirm levels are within acceptable exposure limits before extended work shifts inside the room.

Titan Controls Spartan Series CO2 Monitor vs Titan Controls Atlas 8

Within Titan Controls’ own lineup, the Atlas 8 Digital CO2 Controller is the higher-tier counterpart to the Spartan Monitor. The two units share the same brand engineering and sensor heritage but serve different roles: the Spartan reads, and the Atlas reads and controls. Choosing between them comes down to whether automated CO2 dosing is part of the grow plan or whether the dosing is managed elsewhere.

The Atlas 8 (~$829 MSRP) combines a CO2 sensor with fuzzy-logic hysteresis control and a 15-foot remote sensor cable. It can switch a CO2 generator or regulator on and off based on a programmable setpoint, hold the room within a target band, and adapt the duty cycle as plants pull CO2 down between dosing events. The remote sensor allows the controller box to be mounted outside the canopy zone — relevant in sealed rooms where the controller’s electronics should not sit in the humid plant environment. Growers running larger commercial rooms, multi-zone cultivation spaces, or sealed environments with active CO2 enrichment generally need a controller at this tier. See the Atlas 8 product page for the full feature set.

The Spartan Monitor (~$178) has no setpoint, no remote sensor, no relay output, and no dosing logic. It displays the current CO2 and temperature reading and nothing else. The trade-off is straightforward: the Spartan delivers the same NDIR sensor technology at roughly one-fifth the controller price, and is the right choice when CO2 is being dosed manually, on a timer, or by a separate controller that already handles the relay logic. For growers who only need to confirm what the CO2 level is at any given moment — not act on it — paying for an Atlas’s control hardware adds cost without adding capability they will use.

A second comparison worth noting: the Hydrofarm ECLIPSE F90 Master Environmental Controller is a multi-variable controller that handles CO2, humidity, and temperature on a single device with a 14.5 Amp relay output. It overlaps in price band with mid-tier Titan controllers and is the appropriate cross-brand alternative when a grower wants a single all-in-one controller rather than separate dedicated devices for each variable — the philosophy opposite to the Spartan Series’ single-function approach.

Compatibility & Operating Range

The Spartan Series CO2 Monitor is designed for indoor grow-room and greenhouse use on standard North American 120 V / 60 Hz electrical systems. It is powered by an included USB adapter that plugs into a standard NEMA 5-15R outlet. The unit is not rated for 240 V circuits and is not waterproof.

Compatible cultivation environments: Indoor grow tents, sealed grow rooms, propagation chambers, drying/curing rooms (for monitoring rather than control), and greenhouses up to the size where a single point-source reading is representative of canopy conditions. For larger commercial spaces, multiple monitors or a controller with a remote sensor cable will give better coverage.

CO2 source compatibility: Because the Spartan Monitor is monitor-only (no relay output), it is compatible with any CO2 dosing approach the grower already runs — CO2 tanks with regulators, propane or natural-gas CO2 generators, compressed CO2 bottles on timers, or biological CO2 sources such as CO2 bags. The monitor simply reports the resulting ppm in the room regardless of how the gas was introduced.

Placement guidance: Mount or place the monitor at canopy height in the plant zone, away from direct intake or exhaust air paths that could give an unrepresentative local reading. Avoid placing it directly beside a CO2 emitter (which will read artificially high) or directly in front of an intake fan drawing fresh air into the room (which will read closer to ambient outdoor CO2 of ~420 ppm rather than the actual room average).

Humidity tolerance: The dust- and moisture-resistant plastic housing is rated for typical indoor cultivation humidity (50–75% RH). It is not rated for direct condensation contact or for outdoor use. Pair it with a two-way humidity control in storage or curing applications where ambient RH must be held in a tight range, and keep the monitor out of any zone that experiences direct misting.

Operating temperature: The unit is designed for typical indoor grow-room temperatures (roughly 60–90°F / 15–32°C). Operation outside that range may affect both the sensor’s accuracy and the readout reliability. For greenhouses that experience large diurnal swings, position the monitor in a sheltered location away from direct sunlight on the sensor enclosure.

What it does not do: The HGC702026 Spartan Monitor has no relay output, no setpoint programming, no remote sensor port, no app or Bluetooth connectivity, and no data-logging interface. It is a real-time display only. If any of those functions are required, the controller variant (HGC702025) or one of the higher-tier Titan Controls Atlas controllers is the appropriate choice.

Usage Guidelines

The Spartan Monitor is a continuous-read device. Once plugged in and positioned, it displays the current CO2 concentration and ambient temperature without further configuration. The guidelines below cover practical day-to-day use and how to interpret the readings in a cultivation context.

Sensor warm-up: NDIR sensors typically need a few minutes after power-on to stabilise their reading. When the monitor is first plugged in, the initial reading may drift for the first 5–10 minutes before settling. Wait for the value to stabilise before drawing any conclusion about room conditions.

Target CO2 levels by growth stage: Ambient outdoor CO2 is approximately 400–420 ppm. In an indoor space without active dosing, CO2 typically sits between 300 and 500 ppm depending on ventilation rate and plant load. Supplemented rooms commonly target 800–1,500 ppm during lights-on for vegetative and flowering stages. Cultivars and plant densities vary — consult cultivar-specific guidance, but use the monitor’s reading to confirm the room is hitting whatever target your dosing system is programmed for.

Reading interpretation — lights-on vs lights-off: Plants only take up CO2 during lights-on when photosynthesis is active. During lights-off, plant respiration releases CO2 back into the air, and concentrations will rise above the dosed target if the room is sealed. This is normal and not a fault of the monitor. CO2 dosing systems should be programmed to run only during lights-on to avoid wasting gas and to avoid uncomfortable concentrations for personnel entering the room.

Temperature reading: The monitor’s temperature reading reflects ambient air at the device location, not leaf-surface temperature. For most management purposes the two are close enough that the ambient reading is useful, but in rooms with very high light intensity, leaf temperature can run several degrees above ambient. Use a separate infrared leaf thermometer if precise canopy-temperature management is required.

When the reading looks wrong: If the displayed CO2 value is implausibly high (over 2,500 ppm in an unsupplemented space) or implausibly low (well under 300 ppm with people working in the room), check the device’s placement first. A monitor sitting directly in an intake airstream will read outdoor ambient; a monitor sitting next to a CO2 emitter or a person’s exhalation point will read elevated. If placement is correct and the reading still looks wrong, compare against a second known-good monitor before assuming the Spartan’s sensor has drifted.

Daily routine: A common workflow is to glance at the monitor each time the grower enters the room and note the current value relative to the expected band. Repeated low readings during lights-on indicate the dosing system is undersized for the canopy load or that infiltration is high. Repeated high readings indicate the dosing system is over-running, the timer schedule is too long, or the room is more sealed than the dosing program assumes. The monitor is an inspection tool; act on the readings by adjusting whatever controls the gas delivery.

How to Set Up the Titan Controls Spartan Series CO2 Monitor

The Spartan Monitor ships ready to use with a USB power supply included. Setup is straightforward and requires no programming. The steps below cover unboxing, placement, and initial verification.

1. Unbox and inspect. Remove the monitor and the included USB power adapter from packaging. Inspect the unit for any shipping damage to the screen or enclosure. The dual-beam NDIR sensor is mounted internally and does not require external installation.
2. Choose a placement location. Identify a location at canopy height in the area where you want to track CO2 concentration. Avoid placing the unit directly in front of an intake fan, directly beside a CO2 emitter, or in a zone that will receive direct misting from a humidifier or irrigation system. A wall mount or a shelf at plant level near the centre of the room gives the most representative reading.
3. Connect the USB power supply. Plug the USB cable into the back of the monitor and the wall adapter into a standard grounded 120 V / 60 Hz NEMA 5-15R outlet. The display should illuminate within a few seconds. If the display does not light up, verify the outlet is live and the USB connections are fully seated.
4. Allow the sensor to warm up. The NDIR sensor needs roughly 5–10 minutes after first power-on to stabilise. During this period the displayed CO2 value may drift. Wait for the reading to settle before noting the baseline value.
5. Note the baseline reading. With the room at its normal operating condition (lights on, dosing system running its normal program, plants in their normal position), record the displayed CO2 value. This is your room baseline against which to compare future readings.
6. Verify against expectation. Compare the displayed value to what you expect. An unsupplemented indoor room with healthy plant load during lights-on typically reads 300–500 ppm. A room with active CO2 dosing should read in the range your dosing system is programmed for (commonly 800–1,500 ppm). If the reading is far outside the expected band, re-check placement before concluding the dosing system needs adjustment.
7. Establish a daily check routine. Glance at the monitor each time you enter the grow space. Track readings across lights-on and lights-off cycles. Use the temperature readout alongside the CO2 reading to spot conditions where elevated CO2 is being delivered into an over-warm or under-warm canopy — combinations where CO2 uptake is suboptimal.
8. Periodic placement review. Every few weeks, verify the monitor’s placement is still representative as the canopy grows. A monitor that started at canopy height for seedlings may end up below the canopy by mid-flower, which can affect the local reading. Reposition as needed to keep the sensor in the active plant zone.
9. Long-term sensor verification. NDIR sensors are stable but not immune to drift over multiple years of operation. If the monitor’s reading begins to consistently disagree with a known-good second device or a calibration gas reference, the unit may have reached the end of its useful sensor life and should be replaced rather than recalibrated.

Sources & Further Reading