How to Install a Mars Hydro Inline Duct Fan

Good ventilation is critical to the success of any indoor garden. Without adequate airflow, plants can suffer from temperature extremes, stagnant air, and poor humidity control, all of which can hinder growth or even damage your crops. The right airflow maintains consistent temperatures, balances moisture levels, and provides fresh CO₂, giving your plants everything they need to thrive.

Mars Hydro offers top-notch ventilation solutions with advanced cooling and filtration systems designed for your grow tent. The inline duct fans efficiently manage airflow and purify the air to ensure perfect climate control. Available in 4" and 6" sizes, with manual or smart controls, the Mars Hydro ventilation series makes it easy to choose the ideal setup for your grow space. This article serves as a tutorial demonstrating how to install and use a Mars Hydro inline duct fan kit inside a grow tent.

Installation Procedures

Proper ventilation is key, and with your Mars Hydro inline duct fan in hand, it's time to start the installation. Follow these straightforward steps to ensure a smooth setup for your grow tent.

Step 1: Check the Includes

You can buy the inline duct fan separately and pair it with other accessories, or opt for the Mars Hydro inline duct fan combo, which includes: 

• Inline duct fan
• Carbon filter
• Flexible duct tube
• Speed controller/Thermostat controller
• Hanging straps
• Duct clamps

Step 2: Hanging the Fan 

Unbox all components. First, thread the hanging straps through the fan’s hanging loops. Secure the straps around your grow tent’s top poles and tighten them to suspend the fan at the desired height.

Step 3: Connecting the Carbon Filter

Hang the carbon filter using the same method. Ensure proper orientation—the arrow on the fan should point away from the carbon filter and toward the exhaust vent. Then, connect the fan to the filter.

Step 4: Connecting the Duct Tube

Attach the flexible duct tube to the fan’s exhaust vent. Use duct clamps to secure the connection and prevent air leaks. Trim the ducting if needed for a snug fit.

Note: Be cautious, the duct clamps can be sharp.

Step 5: Connecting the Controller (Optional)

If you have the fan combo with a speed controller or a thermostat controller, follow these steps:

1. Plug the controller’s connection cable into the RJ interface on the fan.
2. Plug the probe sensor into the probe jack on the controller (don’t forget to remove the cap on the sensor).
3. Position the probe sensor near your plants to accurately monitor the environment.

Step 6: Connecting to the MarsPro App (Optional)

The 2025 iFresh Smart Duct Fan can be controlled using the MarsPro app instead of the physical controller, but this requires purchasing the MarsPro Add-on Pack. Models released before 2025 can connect directly to the MarsPro app via Bluetooth without any additional accessories. 

1. Plug the fan into power and connect the iConnect USB to the fan’s port.
2. Insert the knob controller into the fan’s RJ interface.
3. Rotate the knob three or more full turns (each covering over 50% of the scale) to activate pairing mode.
4. Open the MarsPro app, add the device, and follow the prompts to connect to Wi-Fi. (If you need to reconnect your fan to a new Wi-Fi network, simply repeat the steps above.)
5. Once connected, unplug the knob controller from the RJ interface and insert the sensor to complete the network setup. (If the sensor doesn’t appear in the app, try unplugging and reconnecting the USB.) 

How to Replace the Activated Carbon

After a long period, the activated carbon in the filter will become ineffective, at which point you will need to replace it with new activated carbon. The steps are as follows:

1. Unscrew the 3 side screws on the top cover and lift off the metal lid.
2. Take out the sponge plug covering the activated carbon.
3. Pour out the old activated carbon and refill with fresh carbon
4. Reverse the previous steps to reinstall the filter.

You can also check the installation video published by Mars Hydro: