CO2GRO C2 EXT CO2 Controller with External Sensor Probe

Take full control of your grow room environment with the CO2GRO C2 EXT CO2 Controller, available at Holland Horticulture. Designed for precise CO2 monitoring and dosing, this advanced controller allows growers to accurately regulate CO2 levels and optimise plant growth through every stage of development.

Accurate CO2 Monitoring with External Probe

The C2 EXT features an external CO2 sensing probe that measures carbon dioxide levels directly within your grow space, while keeping the main controller unit safely positioned outside. This ensures accurate readings in enclosed environments without exposing the controller to heat or humidity.

Precision CO2 Control & Dosing

Fine-tune your CO2 levels with ease using this intuitive controller. Designed to increase or decrease CO2 output as needed, it allows you to maintain optimal concentrations between 1,000–1,200ppm for maximum photosynthetic efficiency and plant performance.

Advanced NDIR Sensor Technology

Equipped with a dual-channel NDIR CO2 sensor, the C2 EXT delivers highly accurate and reliable CO2 readings. This ensures consistent monitoring and precise environmental control, helping growers avoid fluctuations that can impact plant growth.

User-Friendly Display & Smart Features

An easy-to-read backlit LCD screen provides clear visibility of CO2 levels and system settings. Additional features such as day and night detection and built-in timelapse charting allow you to track historical CO2 concentrations and optimise your grow strategy over time.

Simple Setup & Complete Kit

The CO2GRO C2 EXT is ready to use straight out of the box with no assembly required. Each unit includes:

• C2 EXT Controller Unit
• External CO2 Sensor Probe
• Velcro Mounting Strip
• Screws for installation
• User Manual

The Science of CO2 Enrichment

Carbon dioxide is essential for photosynthesis, enabling plants to convert light into energy. By increasing CO2 levels above ambient conditions (~400ppm), growers can accelerate plant growth, improve nutrient uptake, and increase overall yield.

Maintaining CO2 levels between 1,000–1,200ppm in indoor environments helps maximise photosynthesis, resulting in faster growth cycles and improved crop quality.

Key Benefits of CO2 Control

• Boosts photosynthesis for faster plant growth
• Increases yields and overall crop output
• Enhances plant quality and density
• Improves environmental consistency

Optimising Your Grow Room with CO2

For best results, use CO2 enrichment during the light cycle and maintain proper airflow to evenly distribute CO2 throughout your grow space. Pairing this controller with a CO2 generator or tank system allows full automation and precise environmental control.

Grow room temperatures should be maintained between 28–32°C when supplementing CO2, especially under LED lighting, to ensure optimal plant metabolism and performance.

Buy CO2GRO CO2 Controllers at Holland Horticulture

Upgrade your grow room with the CO2GRO C2 EXT CO2 Controller and achieve precise CO2 management for stronger, faster-growing plants and higher yields.