Troubleshooting

Common problems, contamination identification, stalled growth, and controller fault diagnosis.

Colonisation Problems

No Colonisation After 14 Days

If you see no signs of mycelium growth 14 days after inoculation, something has gone wrong. Work through these causes in order:

Possible Cause	Diagnosis	Solution
Temperature too low	Check your incubation temperature. Below 20°C, growth is extremely slow. Below 15°C, most species stop growing entirely.	Move jars to a warmer location (24–27°C). Use the controller's temperature monitoring to verify.
Dead spores / bad syringe	If the syringe was old, stored improperly (left in heat or frozen), or from an unreliable vendor, the spores may not be viable.	Try a new spore syringe from a reputable vendor. Consider testing on agar first.
Grain too wet	Excess moisture in the grain creates anaerobic conditions that inhibit mycelium. Look for pooled water at the bottom of jars or grains that look slimy.	Grain preparation needs adjustment next time. The current jars may recover if only slightly over-hydrated — give them another week.
Grain too dry	If the grain was under-hydrated before sterilisation, the spores lack the moisture needed to germinate.	Unfortunately, you cannot fix this after sterilisation. Prepare new jars with proper hydration.
Contamination (not visible yet)	Bacterial contamination can inhibit mycelium growth without showing obvious visual signs in the early stages. Smell the jar — sour, sweet, or fermented odours indicate bacteria.	If you suspect bacterial contamination, start over with new jars. Review your sterilisation procedure.

Tip: If using a spore syringe, always test it on an agar plate first. If the spores germinate on agar within 5–7 days, they are viable. If nothing grows on agar, the syringe is the problem.

Contamination Identification

Green Mould (Trichoderma)

Trichoderma is the most common and most devastating contaminant in mushroom growing. It appears as bright green patches, often starting small and spreading rapidly.

Appearance: Starts as white mycelium that is difficult to distinguish from mushroom mycelium, then turns bright green as it sporulates. The green colour is unmistakable once it appears.
Speed: Trichoderma grows extremely fast — a small patch can cover an entire tub in 48 hours.
Location: Can appear anywhere — on grain, on substrate, or on the surface.

Danger: If you see green mould in a grain jar or monotub, discard it immediately. Do not try to save it. Do not open contaminated containers indoors — trichoderma releases billions of spores that will contaminate your growing area. Seal the container in a plastic bag and dispose of it outside. Clean and disinfect your growing area thoroughly before starting again.

Cobweb Mould

Cobweb mould (Dactylium mildew) is a fast-growing, wispy grey mould that looks like spider webs stretched over the substrate surface.

Appearance: Wispy, grey, very fluffy and aerial. Grows upward away from the substrate rather than hugging it. Mushroom mycelium, by contrast, is denser and whiter.
Speed: Can cover the entire surface in 24–48 hours.
Cause: Usually caused by stagnant air (insufficient FAE) and high humidity.

Treatment:

Increase FAE immediately. On the controller, increase fan duty cycle or switch to a higher FAE setting.
Spray affected areas directly with 3% hydrogen peroxide (H2O2). Cobweb mould is one of the few contaminants that can be treated. The H2O2 will fizz on contact and kill the cobweb mould without harming mushroom mycelium.
Monitor closely for 48 hours. If the cobweb returns, increase FAE further.

Tip: Many beginners mistake healthy tomentose (fluffy) mycelium for cobweb mould. The key difference is colour and density: cobweb mould is grey and extremely wispy, while healthy mycelium is white and more substantial. If in doubt, spray a small area with H2O2 — cobweb mould will fizz and dissolve, while healthy mycelium is unaffected.

Wet Rot / Bacterial Blotch

Bacterial contamination typically shows up as slimy, wet-looking areas on the grain or substrate, often with an unpleasant sour smell.

In grain jars: Grains look wet, slimy, or discoloured (yellow-brown). A sour or fermented smell when you open the jar. Often caused by over-hydrated grain or insufficient sterilisation time.
On mushrooms (bacterial blotch): Brown, slimy patches on mushroom caps. Caused by water sitting on caps for too long. Not dangerous, but unsightly and indicates too much moisture.

Solutions:

For grain jars: discard contaminated jars. Improve grain preparation (dry grain surfaces more thoroughly) and ensure full 90-minute sterilisation.
For bacterial blotch on mushrooms: increase FAE to reduce surface moisture. Avoid misting directly onto mushroom caps. Harvest affected mushrooms promptly.

Fruiting Problems

Pins Forming Then Aborting

Pin aborts are small pins that begin to form but stop growing, turn dark, and shrivel. Some aborts are normal (especially in dense pin sets), but widespread aborting indicates an environmental problem.

Cause	Signs	Solution
Humidity too low	Pins dry out and shrivel. Substrate surface looks dry and cracked.	Increase humidity target on the controller. Check that the humidifier is working. Mist the tub walls (not the substrate) if needed.
Temperature swings	Aborts after a sudden cold or hot spell. Check controller temperature history for spikes.	Stabilise the room temperature. Ensure the controller's heater/cooler is functioning. Move the tub away from windows or drafts.
Too many pins (competition)	Very dense pin set where some pins abort while others continue growing. This is natural thinning.	No action needed. The mycelium can only support so many mushrooms. The strongest pins survive.
Contamination stress	Aborts concentrated near a discoloured area of substrate.	Check for hidden contamination. If found, see the contamination section above.
CO2 too high	Pins form but grow very slowly and abort. Usually accompanied by long, thin stems on the surviving mushrooms.	Increase FAE on the controller. Check that fans are actually spinning.

Long Thin Stems, Small Caps

Mushrooms with disproportionately long, thin stems and tiny caps are a classic sign of insufficient fresh air exchange (FAE). The mushrooms are "reaching" for oxygen.

Cause: CO2 concentration too high inside the tub. Mushrooms produce CO2 as they grow and need fresh air to develop properly.
Solution: Increase FAE on the controller. Bump up fan speed or duty cycle. Check that fans are not blocked, disconnected, or failed. Verify that the controller's CO2 sensor (if equipped) is reading accurately.

Mushrooms Growing Sideways or Toward Holes

Mushrooms growing sideways, toward fan holes, or only at the edges of the tub are responding to light or fresh air gradients.

Cause: Mushrooms use light and fresh air as directional cues for growth. If light is only coming from one direction or fresh air is only entering from the sides, mushrooms will grow toward those sources.
Solution: Provide ambient overhead lighting (not direct sunlight — any dim ambient or indirect light is sufficient). Ensure air exchange is distributed evenly across the tub, not just blowing from one side. The controller's fan configuration should create cross-flow ventilation.

Substrate Drying Out

If the substrate is pulling away from the walls of the tub, cracking on the surface, or feeling significantly lighter than when you started, it is drying out.

Cause	Solution
Humidity setting too low	Increase the humidity target on the controller to 85–95% during fruiting.
FAE too high (fans running too much)	Reduce fan speed or duty cycle. High airflow evaporates moisture faster than it can be replaced.
Room humidity very low	The controller can only work with what it has. If your room is very dry (heated homes in winter, air conditioning), consider adding a humidifier to the room or connecting one to the controller via a smart plug.
Lid not sealing	Check that the tub lid fits properly. Gaps allow moisture to escape. Seal gaps with micropore tape if needed.
Substrate too thin	Thin substrate (under 5 cm) dries out much faster. Use a thicker layer (7–10 cm) in future grows.

Controller Issues

Contamination Warning on Dashboard

The controller monitors environmental patterns that may indicate contamination. If you see a contamination warning:

Visually inspect the tub. Look for any discolouration on the substrate surface — green, black, orange, or pink patches.
Check the sensor data. The controller may have detected unusual temperature spikes (exothermic contamination activity) or unexpected CO2 patterns.
Smell test. Open the tub briefly and smell the air. A healthy tub smells earthy and mushroomy. Sour, sweet, or chemical smells indicate contamination.
If contamination is confirmed, stop the grow and discard the substrate. See the contamination section above.
If no contamination is found, the warning may have been triggered by environmental fluctuations. Dismiss the warning and continue monitoring. If it recurs, investigate more thoroughly.

Sensor Faults

If the controller reports a sensor fault, it means it is not receiving valid data from one or more sensors.

Fault	Possible Cause	Solution
SHT31 not detected	Loose I2C connection, damaged cable, or sensor failure.	Check the cable connections at both the sensor and the controller board. Reseat the connector. Try a different cable if available. If the sensor was exposed to liquid water, it may need to dry out or be replaced.
SHT31 reading out of range	Sensor saturated with moisture, or sensor placed in direct airflow giving inaccurate readings.	Move the sensor away from direct fan airflow. If the sensor is wet, remove it and let it dry completely. A hair dryer on low heat (not hot) can help. Ensure the sensor is not touching the substrate surface.
CO2 sensor not detected	Loose connection, sensor not powered, or incompatible sensor model.	Check the wiring. Ensure the sensor is receiving power (most CO2 sensors have a status LED). Verify you are using a supported sensor model.
CO2 reading stuck at 400 ppm	Sensor may be faulty or need calibration. 400 ppm is ambient outdoor CO2 — inside a tub it should be higher.	Try recalibrating the sensor through the controller settings. If calibration fails, the sensor may need replacement.
Temperature readings erratic	Electrical interference, loose connection, or sensor damage.	Check for loose wires. Route sensor cables away from fan motor wires and power cables. Ensure ground connections are solid.

Warning: When a sensor is faulted, the controller cannot accurately manage conditions. Depending on your configuration, it may run fans at a safe default speed or stop controlling entirely. Resolve sensor faults promptly to avoid crop damage from uncontrolled conditions.

Smart Plug Connection Issues

If the controller cannot communicate with your smart socket:

Issue	Possible Cause	Solution
Smart plug not responding	Smart plug is off, unplugged, or has lost WiFi connection.	Check that the smart plug is powered on and connected to your WiFi network. Try accessing the plug's web interface directly in a browser using its IP address.
Smart plug IP changed	Your router assigned a new IP address to the smart plug via DHCP.	Find the new IP address in your router's DHCP client list and update it in the controller settings. Better yet, assign a static IP to the smart plug in your router's DHCP settings to prevent this from happening again.
Timeout errors	Weak WiFi signal between the controller and the smart plug, or network congestion.	Move the smart plug closer to your WiFi router, or add a WiFi extender. Check that your network is not overloaded.
Smart socket not compatible	The smart socket is not compatible or not responding.	Ensure the smart socket is compatible and connected to the same WiFi network. Check the controller documentation for supported smart socket models.
Controller and plug on different networks	The controller and smart plug are on different WiFi networks or VLANs.	Ensure both devices are on the same network and subnet. Check that your router does not have AP isolation or client isolation enabled.

Tip: Assign static IP addresses to both your controller and smart sockets in your router's DHCP settings. This prevents IP address changes from breaking the connection. Most routers have a "DHCP reservation" or "static lease" option — use the device's MAC address to reserve a fixed IP.

Spectrum Sensor Not Detected

If the optional light spectrum sensor is not appearing on the dashboard:

Check I2C wiring. Ensure the sensor is connected to the same SDA/SCL bus as your other sensors. Verify that the SDA, SCL, VCC, and GND pins are all securely connected.
Reboot the controller. The spectrum sensor is detected during boot or a sensor scan. Try restarting the controller after connecting the sensor.
Check for address conflicts. If you have multiple I2C devices, ensure the spectrum sensor is not sharing an address with another device on the bus.

General Tips for Avoiding Problems

Cleanliness above all. Most problems trace back to contamination, and most contamination traces back to poor sterile technique. When in doubt, clean more.
Do not over-handle your tubs. Every time you open the lid, you introduce contaminants. Let the controller manage conditions and only open the tub when necessary.
Monitor the controller dashboard daily. The sensor data will show you trends before problems become visible. A gradual humidity drop over days is easier to fix than a bone-dry substrate.
Keep a grow journal. Record dates, temperatures, observations, and yields for each grow. This helps you identify what works and troubleshoot recurring issues.
Start simple. Use proven techniques (CVG substrate, Golden Teacher or B+ strain, standard monotub) until you are confident in the basics before experimenting.
Use the controller's data export. If you need help troubleshooting, the controller can export its sensor logs. This data is invaluable for diagnosing environmental issues.