How do I calibrate the CO2 sensor?
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Over time, CO₂ sensors naturally drift, leading to inaccurate readings. To ensure precise data and optimal plant growth, we recommend calibrating your Grow Sensor’s CO₂ sensor every six months.
Overestimated or underestimated CO₂ levels can lead to inefficient CO₂ supplementation, wasting resources or stunting plant growth.
Incorrect readings may cause poor climate control adjustments, reducing yield and plant health.
Regular calibration ensures accurate CO₂ monitoring, allowing for better environmental control and improved plant performance.
Before you start:
Choose the right calibration environment
Calibrate outdoors in fresh air, away from traffic, buildings, or direct sunlight. Outdoor air typically contains ~420 ppm CO₂, providing a reliable baseline.
Check battery levels
Ensure your Grow Sensor has enough battery to complete the process.
Avoid enclosed spaces
Do not calibrate indoors, in a greenhouse, or near plants, as CO₂ levels may be artificially elevated.
Move the Grow Sensor outdoors
Find an open-air location, away from buildings and direct sunlight.
Turn on the sensor
The green LED will flash briefly as it powers up.
Wait up to 25 seconds
The sensor may need time to complete background tasks.
Press and release the button when the LED turns purple
This enters CO₂ calibration mode.
Wait for the purple LED to flash for up to 60 seconds
The sensor is preparing to calibrate.
Press and release the button again within 60 seconds
The purple LED will flash faster, indicating
Calibration begins:
Fast-flashing green LED (30 seconds) – The sensor is actively calibrating.
Fast-flashing red LED (30 seconds) – The calibration process is completing.
Calibration complete
The LED will flash white once, confirming successful calibration.
Return the Grow Sensor to your grow environment
Your CO₂ sensor is now recalibrated and ready to use.
For a full breakdown of button functions, check out the .
If calibration fails, the red LED will continue flashing instead of flashing white at the end.
Calibrated in an enclosed or CO₂-rich environment → Move the sensor to an open outdoor space and try again.
Calibration was interrupted → Restart the process from step 1.
Battery too low → Charge the sensor and attempt calibration again.
To abort the calibration process, press and hold the button for 5 seconds. The sensor will return to normal operation.
Your Grow Sensor will automatically wake up and resume normal readings. However, prolonged outdoor exposure isn’t recommended, so be sure to bring it back inside once calibration is complete.
Still have questions? Contact us at we’re happy to help!