26 · LightADVANCED
Secondary, dimmable, and UV lights
A zone can have more than one light, each with its own regime. The main one defines the photoperiod; the rest hang off it or run on their own.
The presets for a secondary light
| Preset | What it does | What you set |
|---|---|---|
| Sync | Mirrors the main light's window exactly. | Nothing. |
| Undercanopy | Turns on with the main light and turns off earlier. | How many minutes earlier (0 to 120). |
| End-of-day far-red | A short pulse after the main light turns off. | Pulse length (5 to 30 min) and how long after it starts (0 to 30 min). |
| Germicidal UV-C | A germicidal pulse with the room empty. | See the box below. |
| Custom | Its own window relative to the light, or an independent timer. | Everything. |
Declared photoperiod and effective photoperiod
- A secondary light with an offset stretches the tent's real photoperiod. A real case: the zone declared 16/16 and the tent was doing 17/15 because one light opened an hour earlier.
- That's why the card shows the effective photoperiod when it differs from the declared one.
- Far-red and UV-C pulses don't count as stretching as long as they last 30 minutes or less: they step on the dark on purpose.
Brightness curve
| Setting | Range | What it does |
|---|---|---|
| No ramp | — | Turns on straight to the ceiling percentage. |
| Fade | 5 to 120 min per side (default 30) | Linear sunrise and sunset, with independent durations. |
| Curve | — | Smooth rise and fall, sine-shaped. |
| Ceiling (plateau) | 1 to 100 % | The day's maximum brightness. You drag it on the chart. There is no 0: turning off is the switch's job. |
Do this
If you have two identical lights, leave one on sync and don't touch anything on it. The offset only makes sense when the second light has a different job.
Avoid this
Don't set a far-red pulse several hours long. That's not a pulse anymore: it's a whole photoperiod hiding behind a preset's name.
How urgent it is
EssentialNothing: one light is enough.
ImportantSecondaries on sync if you add fixtures.
OptionalUndercanopy, far-red, UV-C, and the brightness curve.