Proper airflow is the difference between a healthy grow and a mold disaster. Calculate your CFM needs, then shop inline fan + carbon filter kits from the top brands.
Why Airflow Matters
Your grow tent is a sealed environment. Without active ventilation, heat builds up, humidity spikes, CO₂ depletes, and stale air creates the perfect conditions for mold, mildew, and pests. A properly sized inline fan solves all of this at once.
The Rule: 1× Air Exchange Per Minute
The standard target is to replace all the air in your tent once every minute. That means your fan's CFM rating should equal (or exceed) your tent's cubic footage. Add 25% overhead for a carbon filter, ducting bends, and future-proofing.
8" duct — 4×4 to 5×5+ tents, 700+ CFM for large spaces
Digital vs. Knob Controllers
Digital controllers (GrowHub, MarsPro APP, speed dial) let you set exact fan speeds, program schedules, and respond to temperature/humidity sensors. Knob controllers are simpler and cheaper — manual speed adjustment, no automation. For most growers, digital is worth the extra cost.
Carbon Filter Sizing
Your carbon filter must match your fan's duct size. A 6" fan needs a 6" filter. Mismatched sizes reduce airflow and odor control. All kits below include a matched filter — no guesswork needed.
💨 CFM Calculator
Enter your tent dimensions to find the minimum CFM you need.
208
Min CFM
260
Recommended CFM
6"
Suggested Duct
Shop Inline Fan Kits
Fan + carbon filter + ducting kits. Filter by duct size, brand, or controller type.
