Follow this stage by stage. Aim is the target; stay inside the OK range; if a reading hits the Act if column, correct it. Jot what you actually measure in Your reading — a pencil is a sensor, and your notes are how the recipe gets better. The same numbers a controller would use as setpoint and alarm; you're the controller today.
| What | Aim | OK range | Act if | Your reading |
|---|---|---|---|---|
| Daily light (DLI) | 9 mol/m2/d | 5.1–13.8 mol/m2/d | < 4.2 or > 15.6 mol/m2/d | |
| Photoperiod | 16 h | — | — | |
| Air temp — day | 21 °C | 15.3–27.6 °C | < 12.6 or > 31.2 °C | |
| Air temp — night | 18 °C | 13.6–23 °C | < 11.2 or > 26 °C | |
| Humidity | 57.5 % | 42.5–74.75 % | < 35 or > 84.5 % | |
| VPD | 0.8 kPa | 0.51–1.15 kPa | < 0.42 or > 1.3 kPa | |
| CO₂ | 600 ppm | 340–920 ppm | < 280 or > 1040 ppm | |
| Air changes | 22.5 ACH | 12.75–34.5 ACH | < 10.5 or > 39 ACH |
| What | Aim | OK range | Act if | Your reading |
|---|---|---|---|---|
| Root-zone temp | 20 °C | 15.3–25.3 °C | < 12.6 or > 28.6 °C | |
| Dissolved O₂ | 7 mg/L | 5.1–9.2 mg/L | < 4.2 or > 10.4 mg/L | |
| Substrate moisture | 60 % | 42.5–80.5 % | < 35 or > 91 % |
Watch for: aerial — condensation on cold surfaces (wet leaves invite disease), VPD drifting out of band. Root — deficiency on new growth, EC/pH creep; log a reading each visit.