Turtles
Alligator snapping turtle care guide
Macrochelys temminckii
A huge (100+ lb) ambush predator. Expert-only, protected in many states.
Aquatic — water volume and floor area first
New to reptiles? Check your keeper level first →Alligator snapping turtle enclosure size
Aquatic — water volume and floor area first. An adult alligator snapping turtle should live in at least 96" L × 48" W × 24" H; we build toward 120" L × 60" W × 36" H (10 × 5 × 3 ft, roughly 50 sq ft of floor and about a 1122-gallon glass equivalent).
- Hatchling / baby
- 36" L × 18" W × 16" H recommended · min 30" L × 12" W × 12" H
- Juvenile
- 72" L × 24" W × 24" H recommended · min 48" L × 24" W × 18" H
- Adult
- 120" L × 60" W × 36" H recommended · min 96" L × 48" W × 24" H
Temperature and heating
Submersible heater with guard; a gentle basking area is optional.
- Basking / warm surface
- Rarely basks — no hot spot needed
- Warm side (ambient)
- Water 74–78°F
- Cool side (ambient)
- —
- Night
- Water no lower than 70°F
Lighting and UVB
UVB: Low-level UVB beneficial. Run lights on a 12 hours on, 12 hours off photoperiod, on a timer, and replace UVB bulbs on the manufacturer's schedule even while they still emit visible light.
Humidity
Target Not critical — aquatic. The water provides humidity; keep the basking dock fully dry.
Substrate and depth
Bare bottom or sand. Depth: —.
Water and filtration
- Water depth
- Deep enough to submerge but shallow enough to reach air while standing
- Filtration
- Canister filter rated 2–3x the water volume, plus a 25% water change weekly
- Basking dock
- A dry, easily climbed dock under the heat and UVB lamps
Diet and feeding
Fish, crayfish, rodents and turtle pellets.
Enclosure tips and furnishing
- Hides on both the warm and cool sides
- Clean water available at all times
- Clutter — cork, leaf litter, plants — for cover
Build list
- Enclosure at adult size — Buy for the adult footprint to avoid repeated upgrades.
- 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.
Alligator snapping turtle FAQ
How big should an adult Alligator snapping turtle enclosure be?
At least 96" L × 48" W × 24" H, and we recommend building to 120" L × 60" W × 36" H — about 10 × 5 × 3 ft, or a 1122-gallon glass equivalent. Aquatic — water volume and floor area first.
What temperatures does an Alligator snapping turtle need?
Basking or warm surface Rarely basks — no hot spot needed, warm side Water 74–78°F, cool side —, night Water no lower than 70°F. Submersible heater with guard; a gentle basking area is optional.
Does an Alligator snapping turtle need UVB?
Low-level UVB beneficial. Photoperiod: 12 hours on, 12 hours off.
What humidity does an Alligator snapping turtle need?
Not critical — aquatic. The water provides humidity; keep the basking dock fully dry.
What substrate is best for an Alligator snapping turtle?
Bare bottom or sand, at a depth of —.
How big does an Alligator snapping turtle enclosure need to be for a hatchling?
Hatchling / baby: 36" L × 18" W × 16" H recommended, minimum 30" L × 12" W × 12" H. Scale up to the adult footprint as the animal grows.
Is there anything to be careful about when keeping an Alligator snapping turtle?
Protected or restricted in many states — check local laws. The bite can sever fingers; never hand-feed.
Sources
Put this guide to work
Apply these targets to your own alligator snapping turtle record, then log feedings, sheds and weights against them.