Automating an enclosure's lights makes it easier to keep a consistent schedule and create
a gradual transition between day and night. The basking lamp, LEDs and UVB can each run on
their own timer, allowing the enclosure to brighten and darken in stages. Dimming controls
and multiple basking spots on staggered timers can make the transition even more gradual.
A day outside
Sunlight changes in both intensity and balance throughout the day. A solar research
station in Golden, Colorado recorded the clear day shown below. The graph compares direct
solar energy, visible brightness and UVI, with each line scaled to its own daily peak.
Power densityLuxUVI September 17, 2023, at the Solar Radiation Research Laboratory in Golden, Colorado.
Each series is scaled to its own peak: 1014 W/m², 100,400 lux and UVI 7.2. The
power-density instrument measured the direct beam; lux and UVI included scattered
skylight. Data from the SRRL Baseline Measurement System.
Power density builds first in the morning, followed by visible light and then UV. The order
reverses toward dusk: UV fades first, then visible light, followed by power density. The
exact timing and intensity change with place, season and weather.
Dawn and dusk
Turn the basking lamp on first because near-infrared builds earlier than visible light and
UV outdoors. Its soft golden light also creates a gentler first stage of dawn. Turn the
LEDs on fifteen minutes later and add UVB after another fifteen minutes. At dusk, reverse the
order.
With smart plugs
With LumenIZE dimmers
This schedule follows an example shared by Dr. Frances Baines in the Reptile Lighting group. The basking lamp runs from 7:00 am to 7:00 pm. The LED ramps from 0% at 7:15 am to 100% at 7:45 am, then from 100% at 6:15 pm to 0% at 6:45 pm. UVB ramps from 0% at 7:30 am to 100% at 8:00 am, then from 100% at 6:00 pm to 0% at 6:30 pm.
The bars mark the morning switch-on times. Tapered ends show lamps gradually reaching full output. The lamps turn off in the opposite order at dusk.
My enclosure
The same principles can be extended across multiple basking spots. My enclosure has two, each with its own basking, LED and UVB lamps, and the second set begins 15 minutes after the first. Within each set, the basking lamps finish ramping before the first half of the LEDs comes on, followed by the UVB lamps and then the second half of the LEDs.
I use Kasa smart dimmers to slowly ramp the basking lamps. The LEDs that provide UVA1 are not currently dimmable, so they switch on at full output. The UVB lamps are relatively dim, so I see little benefit in ramping them.
Timers
Plain timers or smart plugs can run the stepped schedule. LumenIZE LED and UVB fixtures
can use smooth half-hour ramps. These examples use a 12-hour day. Set the photoperiod for
the species and season by shortening or extending the steady middle of the day.
Tools for automation
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