Grow Tent Humidity (VPD) Dashboard

The default band is higher RH for seedlings/clones (65–70%), falling to 40–50% in late flower (VPD-driven). Treat it as a sensible starting point — your own specification, regulator, equipment manual or product datasheet sets the authoritative limits, and you can read your true band straight off the worst case those documents allow. Edit the readings against whatever band applies to you.

Dense flowers trap moisture, and high humidity in the canopy invites botrytis (bud rot) and powdery mildew that can destroy a crop late, after months of work. Lowering RH to 40–50% in flower keeps the canopy dry and the buds firm, and it nudges VPD into the range that keeps the plant transpiring without stress. Improve airflow through the canopy too — stagnant humid pockets rot even when the tent average looks fine. The reverse applies for clones, which need high humidity to survive with no roots.

Match the interval to the consequence and the rate of change: where an excursion spoils product or risks safety, log continuously (or as often as you can sample); where it is merely informative, daily or per-shift spot checks suffice. The in-range % and excursion count only mean something if your sampling is regular — sparse, irregular readings hide the excursions between them.

Yes — every reading is stored in this browser's localStorage on your device and nothing is uploaded to any server, which also makes the dashboard usable on sites with strict data policies. For shared, audit-grade records across a team or for regulatory retention, export the values into your own system.