RecoveryGeckos
Giant day gecko care guide
Phelsuma grandis
A brightly diurnal, high-UVB arboreal gecko. Planted vertical space and strong lighting are non-negotiable.
Arboreal — vertical height first
Giant day gecko enclosure size
Arboreal — vertical height first. An adult giant day gecko should live in at least 18" L × 18" W × 36" H; we build toward 24" L × 24" W × 48" H (2 × 2 × 4 ft, roughly 4 sq ft of floor and about a 120-gallon glass equivalent).
- Hatchling / baby
- 18" L × 18" W × 24" H recommended · min 12" L × 12" W × 18" H
- Juvenile
- 18" L × 18" W × 36" H recommended · min 18" L × 18" W × 24" H
- Adult
- 24" L × 24" W × 48" H recommended · min 18" L × 18" W × 36" H
Temperature and heating
Overhead halogen at the top of the enclosure, thermostat-controlled.
- Basking / warm surface
- 88–92°F surface at the top
- Warm side (ambient)
- 80–85°F ambient
- Cool side (ambient)
- 72–78°F ambient
- Night
- 68–74°F
Lighting and UVB
UVB: T5 UVB 6–12% (UVI 3–4 at basking) — high requirement. Run lights on a 12–13 hours photoperiod, on a timer, and replace UVB bulbs on the manufacturer's schedule even while they still emit visible light.
Humidity
Target 60–80% with daily drying. Mist morning and evening; live plants stabilise it.
Substrate and depth
Bioactive soil with leaf litter. Depth: 2–3 in.
Enclosure tips and furnishing
- Bamboo and cork verticals
- Large-leaved live plants
- Feeding ledge
- Misting system or daily sprayer
Build list
- Tall planted terrarium (18x18x36+) — They live in the top third of the enclosure.
- T5 UVB 6–12% + halogen — High UVI species; underpowered lighting causes MBD.
- Digital thermostat — Every heat source must run through a thermostat — unregulated heat burns animals.
- Two digital probe thermometers + hygrometer — Read the warm side, cool side and humidity directly — stick-on dials are inaccurate.
- Bioactive substrate and drainage layer — Supports live planting and humidity.
Giant day gecko FAQ
How big should an adult Giant day gecko enclosure be?
At least 18" L × 18" W × 36" H, and we recommend building to 24" L × 24" W × 48" H — about 2 × 2 × 4 ft, or a 120-gallon glass equivalent. Arboreal — vertical height first.
What temperatures does a Giant day gecko need?
Basking or warm surface 88–92°F surface at the top, warm side 80–85°F ambient, cool side 72–78°F ambient, night 68–74°F. Overhead halogen at the top of the enclosure, thermostat-controlled.
Does a Giant day gecko need UVB?
T5 UVB 6–12% (UVI 3–4 at basking) — high requirement. Photoperiod: 12–13 hours.
What humidity does a Giant day gecko need?
60–80% with daily drying. Mist morning and evening; live plants stabilise it.
What substrate is best for a Giant day gecko?
Bioactive soil with leaf litter, at a depth of 2–3 in.
How big does a Giant day gecko enclosure need to be for a hatchling?
Hatchling / baby: 18" L × 18" W × 24" H recommended, minimum 12" L × 12" W × 18" H. Scale up to the adult footprint as the animal grows.
Sources
Put this guide to work
Apply these targets to your own giant day gecko record, then log feedings, sheds and weights against them.