Fanning Mushrooms
Definition: Fanning is the manual introduction of fresh air into a mushroom fruiting chamber, usually by waving the lid or a flat object over the tub to create airflow. The goal is to reduce carbon dioxide (CO2) buildup and provide an oxygen-rich environment for healthy fruiting.
Important: With RyzaPods, fanning is generally unnecessary. Simply removing the dome completely resets CO2 levels because the substrate sits close to the top, preventing CO2 from pooling at the bottom.
Why Does Fanning Mushrooms Matter?
Mushrooms are highly sensitive to CO2 levels during the fruiting stage. Elevated CO2 can cause long, skinny stems and small caps—or prevent pinning altogether. In deep or large tubs, CO2 tends to stratify and settle toward the bottom, especially under the substrate surface. Simply cracking the lid or opening the tub isn’t always enough to displace this heavy CO2 layer.
Fanning helps break that CO2 pocket and brings in fresh air, creating the conditions mushrooms need for proper morphology and abundant pin formation.
How Fanning Works
CO2 Stratification: CO2 is heavier than oxygen, so it sinks to the bottom of deep tubs.
Fanning Action: Manually fanning moves stagnant air out and pulls in fresh air with lower CO2 concentration.
Target Range: The ideal CO2 level during fruiting is roughly 500–800 ppm. Without intervention, levels can exceed thousands in sealed or poorly ventilated tubs.
When to Fan Mushrooms
Deep Tubs: Monotubs or double tubs with significant depth (e.g., >8–10 inches) where stratification occurs.
Minimal Passive FAE: When the setup lacks holes, filters, or vents for steady gas exchange.
Early Fruiting: During the pinning stage and first flush, when CO2 sensitivity is highest.
When You Don’t Need Fanning
RyzaPods: The substrate is close to the lid, so CO2 doesn’t pool. Removing the dome fully resets CO2 levels in seconds.
Shallow Trays or Proper FAE Systems: If the tub is shallow or has well-designed ventilation, fanning is often unnecessary.
How to Fan: Step-by-Step
Open the Tub: Lift or tilt the lid partially to expose the substrate.
Fan Fresh Air: Use the lid itself or a clean, flat object to fan inward and outward 5–10 times.
Close the Lid: Return the tub to its normal position.
Repeat: Daily or twice daily.
Tip: After fanning, mist lightly to maintain surface moisture if needed.
Signs You Need More Fresh Air
Long, skinny stems (CO2 stress).
Small, underdeveloped caps.
Side pinning near the tub walls.
Troubleshooting & Tips
Sanitation: Always use a clean object to fan—contamination can hitch a ride.
Humidity: Fanning can lower humidity, so balance with misting.
