Lab Notes: why we measure the room before we grow in it
Temperature, humidity and airflow decide more grows than any nutrient. A short field guide to logging a room before anything alive goes in — with interruptions from the Commander.
Sample episode — draft copy for owner review. Measurements and photos marked [OWNER] get filled in from the real build.
The Commander’s position is that a true leader can feel the humidity. The data’s position is that he cannot, and neither can you. That is why every phase of this build gets instruments before it gets plants.
Start with temperature and relative humidity, logged at canopy height and near the floor, for at least a few days with the lights and fans running on their real schedule. One reading tells you nothing; a chart tells you when the room drifts, how fast and why.
Next, airflow. Dead corners and still air under a canopy are where mould gets its start. A cheap way to check: log humidity in the worst corner you can find and compare it with the middle of the room. If the corner runs consistently wetter, the air is not moving there.
Finally, calibrate. Two cheap hygrometers side by side will often disagree. Check them against a known reference before you trust either one, write down the offset, and repeat it every few months.
None of this is glamorous. All of it is cheaper than losing a grow. [OWNER: add our first room log once the sensors are in.]