Terrarium Grow Light Wattage Calculator
Calculate grow light watts for a terrarium by volume and plant type.
Get LED watt recommendations for low-light, tropical, and high-light setups.
Terrarium Grow Light Wattage
Plant lighting needs depend on volume of the enclosure and the light requirements of the species inside. Modern LED panels are rated by actual watts drawn, not the legacy “incandescent equivalent” — always check the spec sheet.
Watts per gallon (LED draw — not equivalent watts):
| Plant Type | LED Watts/Gallon |
|---|---|
| Low-light (mosses, ferns, ivy) | 0.5-1.0 |
| Tropical foliage (calathea, peperomia) | 1.0-1.5 |
| Bromeliads / orchids | 1.5-2.5 |
| Carnivorous (Drosera, Pinguicula) | 2.0-3.0 |
| High-light succulents / cacti | 3.0-5.0 |
For a 10-gallon enclosure with tropical foliage: 10-15 W LED.
Adjustments by terrarium height:
- Under 12 inches tall: standard wattage
- 12-18 inches: +20% (light decays inverse-square law)
- Over 18 inches: +40% or use a more focused / higher-PPFD fixture
Adjustments by glass type:
- Clear glass top: standard
- Mesh top: +20% (mesh absorbs/scatters light)
- Frosted glass: +30% (significant light loss)
PPFD vs. wattage: PPFD (μmol/m²/s) is the better metric — it measures photons reaching the plants — but isn’t always listed for hobby fixtures. Watts is a useful proxy for budget LEDs. For premium fixtures with PPFD specs:
- Low-light: 50-100 PPFD
- Tropical: 150-300 PPFD
- High-light: 400-700 PPFD
Photoperiod recommendations:
- Tropical: 10-12 hours
- Carnivorous: 14-16 hours (long-day cycle)
- Succulents: 12-14 hours
- Mosses / ferns: 8-10 hours (low-intensity, indirect feel)
Common LED fixtures and their actual watts:
- Hygger 18W aquarium light: ~12 actual W output
- Sansi 30W bulb: ~30 actual W
- Mars Hydro TS 600: ~100 W actual
- Twinstar 360S: ~22 W actual
Always verify the actual draw from the spec sheet — not the inflated “equivalent” wattage.