Grey oyster
Pleurotus ostreatus · MS-3 · v3.0.0
Straw or sawdust substrate, hanging bags. The classic failure here is CO2, not temperature: a room that holds 2,000 ppm through fruiting gives long stems and caps the size of a coin, and the grower usually blames the strain. Heavy fresh air exchange is the whole recipe.
Spawn run
Advances after 14 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 25.0 °C | 24.3 °C – 25.8 °C | heater, cooler |
| Relative humidity | 85.0 % | 82.5 % – 87.5 % | humidifier |
| Carbon dioxide | 8,000 ppm | 6,500 ppm – 9,500 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 0.2 changes/hour | — | exhaust, intake |
Mycelium wants the CO2 it makes. Ventilating now slows colonisation and invites competitors into an unsealed block.
Vapour pressure deficit at these targets: 0.48 kPa. That is what 85% humidity means at 25.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Primordia initiation
Advances when you mark "pins observed", or after 5 days| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 17.0 °C | 16.4 °C – 17.6 °C | heater, cooler |
| Relative humidity | 91.0 % | 89.5 % – 92.5 % | humidifier |
| Carbon dioxide | 600 ppm | 475 ppm – 725 ppm | exhaust, intake |
| Vapour pressure deficit | 0.17 kPa | 0.13 kPa – 0.21 kPa | humidifier, in advanced mode |
| Light | 12 h at 800 lux | — | lights |
| Fresh air, minimum | 4.0 changes/hour | — | exhaust, intake |
The drop in temperature and the arrival of light and fresh air together are the signal. Change all three at once; changing one at a time gives a slow, uneven pinset.
Vapour pressure deficit at these targets: 0.17 kPa. That is what 91% humidity means at 17.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Fruiting
Advances after 5 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 18.0 °C | 17.3 °C – 18.8 °C | heater, cooler |
| Relative humidity | 88.0 % | 86.5 % – 89.5 % | humidifier |
| Carbon dioxide | 650 ppm | 525 ppm – 775 ppm | exhaust, intake |
| Vapour pressure deficit | 0.25 kPa | 0.20 kPa – 0.30 kPa | humidifier, in advanced mode |
| Light | 12 h at 800 lux | — | lights |
| Fresh air, minimum | 5.0 changes/hour | — | exhaust, intake |
Humidity comes down slightly from pinning. Caps that stay wet split and then rot; the target is a room that feels damp, not one that drips.
Vapour pressure deficit at these targets: 0.25 kPa. That is what 88% humidity means at 18.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Harvest
Advances when you mark "harvested", or after 2 days| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 18.0 °C | 17.3 °C – 18.8 °C | heater, cooler |
| Relative humidity | 85.0 % | 83.0 % – 87.0 % | humidifier |
| Carbon dioxide | 800 ppm | 650 ppm – 950 ppm | exhaust, intake |
| Light | 12 h at 800 lux | — | lights |
| Fresh air, minimum | 4.0 changes/hour | — | exhaust, intake |
Drop humidity a little before picking. Mushrooms harvested dry keep days longer than mushrooms harvested wet.
Vapour pressure deficit at these targets: 0.31 kPa. That is what 85% humidity means at 18.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Rest between flushes
Advances after 7 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 22.0 °C | 21.0 °C – 23.0 °C | heater, cooler |
| Relative humidity | 85.0 % | 82.5 % – 87.5 % | humidifier |
| Carbon dioxide | 2,500 ppm | 2,000 ppm – 3,000 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 1.0 changes/hour | — | exhaust, intake |
Warm the block back up and let it re-colonise the spent zone. Then return to pinning for the second flush.
Vapour pressure deficit at these targets: 0.40 kPa. That is what 85% humidity means at 22.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Alarms
These do not switch anything. They sit outside the control loop deliberately, so that a bug in the control logic cannot also silence the thing that wakes you.
- Air above 30 °C
- Air below 8 °C
- Humidity below 70%
- CO2 above 5,000 ppm
Have Claude read this for you
Optional, off by default, and it uses your own Anthropic API key rather than ours. It is shown the findings this page already computed and is told it may not invent a number — no setpoint, no threshold, no duty cycle. It ranks what matters and says it in two sentences. It is never in the control loop: nothing on your board waits on it, and if it is switched off everything here works exactly the same.
A room review sends about 2,000 tokens and gets back about 600 — roughly US$0.03, or under three rupees.
Get an API key Read the API docs
Paste the key under Settings → Mushroom in the dashboard. It is stored on this site and sent only to api.anthropic.com, only when you press the button.
These targets are derived from published literature, not measured on your substrate, your strain or your room. Treat any recipe you have not validated on your own farm as a hypothesis. The yield log exists so that your second run can correct your first. Literature-derived. Not yet validated on a farm.