UV bar setup guide — Bo Lights

Identify your species' UV zone

Vets and zoos group reptiles into four zones according to their natural sun exposure (Ferguson zones). Each zone has a maximum UVi to reach at the basking spot, where the animal basks under the bar.

Zone 1

Crepuscular or shade-dwelling species

Max UVi at basking spot0.6 – 1.4

Zone 2

Partial shade, occasional basking

Max UVi at basking spot1.1 – 3.0

Zone 3

Partial or full sun exposure

Max UVi at basking spot2.9 – 7.4

Zone 4

Full sun, midday basking

Max UVi at basking spot4.5 – 9.5

Not sure which zone your species belongs to? Your vet, breeder or our team can help.
Reference: Ferguson zones (Ferguson et al., 2010; Baines et al., 2016).

Choose the bar and the height

Measure the distance between the bar and the basking spot. In the table, find the cell whose UVi matches your species' zone: it gives you the right bar and height.

Distance	UV 6%	UV 12%	UV 14%
10 cm	16.7Above zone 4 maximum	24.5Above zone 4 maximum	73.3Above zone 4 maximum
20 cm	9.4Z4	14.5Above zone 4 maximum	32.1Above zone 4 maximum
30 cm	4.8Z3Z4	8.6Z4	13.9Above zone 4 maximum
40 cm	3.0Z2Z3	5.1Z3Z4	6.1Z3Z4
50 cm	2.0Z2	3.1Z3	2.6Z2
60 cm	1.0Z1	1.8Z2	1.1Z1Z2

Swipe to see the full table →

UVi values measured under the bar, with no obstacle. Badges show the zones whose maximum UVi matches the value.

Mesh: take it into account

Mesh between the bar and the animal blocks part of the UV. Depending on the mesh, UVi can drop by roughly 30 to 50%. With mesh, move the bar closer or choose the next intensity up.

Indicative values: the real effect depends on mesh size and material. For a precise setup, check with a UV meter.

Estimate with mesh (−30 to −50%)

Distance	UV 6%	UV 12%	UV 14%
10 cm	8.3 – 11.7	12.2 – 17.1	36.6 – 51.3
20 cm	4.7 – 6.6	7.2 – 10.1	16.1 – 22.5
30 cm	2.4 – 3.4	4.3 – 6.0	7.0 – 9.7
40 cm	1.5 – 2.1	2.5 – 3.6	3.0 – 4.3
50 cm	1.0 – 1.4	1.6 – 2.2	1.3 – 1.8
60 cm	0.5 – 0.7	0.9 – 1.3	0.6 – 0.8

Swipe to see the full table →

Plants and branches: a deliberate gradient

Vegetation filters light and creates shaded areas, just like in nature. That's a good thing: your animal should always be able to choose between an exposed area under the bar and shaded areas, to regulate its own exposure.

Keep the basking spot clear, under the bar, at the chosen distance.
Let plants and branches create shade elsewhere in the terrarium.
Direct or filtered exposure: the animal must be able to move between both.

Typical set-up

The UV bar lights a clear basking spot, at the right distance. Around it, branches and plants create a shade gradient: the animal chooses its own exposure.

UV barAbove the basking spot.

Natural VisionLight and colour, on the same plug.

Optional meshReduces UVi by roughly 30 to 50%.

DistanceMeasured from the bar to the basking spot.

Basking spotClear, directly under the bar.

Shaded zonesPlants and branches: the animal retreats there.

Add Natural Vision

UV bars provide the UV. For light, colour rendering and plant growth, add a Natural Vision bar: up to 8 bars on a single plug.

Unsure about your setup?

Describe your terrarium and your animal: our team will advise you.

Ask for advice See the range