Getting a new pet hermit crab and setting up their habitat is an exciting endeavor! One of the most important decisions is picking the right sized tank for your new crabby friend Selecting an appropriately sized enclosure ensures your hermit crab has plenty of space to thrive So how big should a hermit crab tank be?
Through research and experience, I’ve put together this complete guide on recommended tank sizes for pet hermit crabs We’ll cover ideal minimum gallons, dimensions, and other key factors in choosing the perfect tank for your crab’s needs Read on for everything you need to know about proper hermit crab tank sizes.
Minimum Tank Size Guidelines
As a general rule of thumb for minimum tank sizes:
- 1-2 small crabs (under 1 inch): 10 gallon tank
- 3-5 small crabs (under 1 inch): 20 gallon tank
- 5-10 small crabs (under 1 inch): 30+ gallon tank
- 2-3 large crabs (over 2 inches): 20 gallon tank
- 5-10 large crabs (over 2 inches): 40+ gallon tank
These minimums allow about 2-3 gallons per average sized crab. Larger crabs over 2 inches in diameter will need additional space. Whenever possible, opt for larger tank sizes.
While a 10 gallon tank is acceptable for 1-2 juvenile crabs to start, a 20+ gallon tank is ideal for any number of hermit crabs. Keep reading for more specific guidelines based on crab size and number.
Tank Size by Number and Size of Hermit Crabs
To choose the perfect tank size, you’ll need to consider:
- Number of crabs – The more crabs, the bigger the tank required
- Crab size – Allow 2-3 gallons per 1 inch of crab size. Bigger crabs need more area.
- Future growth – Get a tank that allows room for growth to full adult size up to 5 inches.
Here are the recommended minimum tank sizes:
- 1-2 small crabs (under 1 inch): 10 gallon tank minimum, 20 gallons preferred
- 3-5 small crabs (under 1 inch): 20 gallon tank minimum
- 5-10 small crabs (under 1 inch): 30+ gallon tank minimum
- 2-3 large crabs (over 2 inches): 20 gallon tank minimum
- 5-10 large crabs (over 2 inches): 40+ gallon tank minimum
A good rule of thumb is 2-3 gallons per crab plus 1 extra gallon per inch of crab size. Always choose bigger tanks when possible.
For adult hermit crabs over 2 inches, aim for a minimum 40+ gallon tank. Giant crabs over 5 inches need at least 10 gallons each.
While acceptable for 1-2 tiny crabs, a 10 gallon tank is very small. A 20+ gallon tank provides ample space to add more crabs later as your collection grows.
Tank Shape, Dimensions, and Features
In addition to minimum tank gallons, the ideal shape and dimensions are key for a hermit crab habitat.
Here are some important tips for tank shape and features:
- Rectangular shape is best, not round or curved
- Dimensions should allow 5-10 inches of substrate depth
- Length is more important than height
- Lid or hood needed to hold in heat and humidity
- Proper heating and humidity maintenance accessories
For a 10 gallon tank, recommended inner dimensions are 20 x 10 x 12 inches (L x W x H). This allows adequate substrate depth.
Always choose longer rectangular tanks over tall tanks. Hermit crabs use floor space more than height.
Providing Proper Substrate Depth
One critical factor in hermit crab tank size is allowing enough substrate depth.
Hermit crabs need deep substrate to dig, burrow, and molt successfully. Recommended substrate depth:
- Small crabs under 1 inch: 5 inches
- Medium crabs 1-2 inches: 6-8 inches
- Large crabs over 2 inches: 8-10 inches
The tank must be large enough to provide proper substrate depth for the crabs’ sizes. Extra floor space is also ideal for digging room.
For example, a 10 gallon tank should only house 1-2 tiny crabs since it can realistically fit about 5 inches of substrate.
Upgrading Tank Size As Crabs Grow
Pet hermit crabs grow continuously over their 20+ year lifespan. You’ll need to upgrade tank size as they reach larger sizes.
Some common tank upgrades as hermit crabs grow:
- 10 gallon starter tank → Upgrade to 20 gallons for 2-3 small crabs
- 20 gallon for small crabs → Upgrade to 30+ gallons for 5+ small crabs
- 20 gallon tank → Upgrade to 40+ gallons for large 2-3 inch crabs
Try to buy the biggest suitable tank you can from the start. This avoids multiple upgrades down the road. But do plan upgrades as crabs reach adult sizes over 2 inches.
Giving Hermit Crabs Proper Space to Thrive
Providing adequate tank space is crucial for hermit crabs’ health and activity levels. By following these guidelines, you can ensure your crabs have room to dig, climb, and thrive.
While the minimum sizes may be tempting, always opt for larger tanks when possible. More room to roam leads to happier, healthier pet hermit crabs.
Review these recommendations to pick the ideal tank size based on number of crabs, current and adult sizes, substrate needs, and other factors. Giving your hermit crabs sufficient room to grow will result in active, long-lived pets that fully utilize their habitat spaces.
The Substrate
Avoid gravel or wood shavings. Good substrate options for a hermit crab tank include:
- Sand: Hermit crabs prefer sand as a substrate because they like to burrow into it. Playground sand, available at home improvement stores, works well and is inexpensive, although aquarium sand is also suitable. Consider rinsing, drying, and baking the sand at 300 F to sterilize it. It can be rewashed and reused. Calcium-based sands are available in various colors but are more expensive.
- Fiber Bedding: Products like coconut fiber-based bedding, such as Forest Bedding made for reptiles, can be used in hermit crab tanks. The finely ground fiber resembles soil and is excellent for burrowing.
- Crushed Coral: Although a good choice, providing an additional area with Forest Bedding or sand is advisable, as hermit crabs may prefer these for molting.
Lights
Previously, it was believed that hermit crabs were nocturnal and that lights could stress them. However, low-wattage or special night bulbs can be beneficial. Many owners find their crabs are more active and bask near lights when lighting is added to the tank.
- Daytime and nighttime cycles: Provide a light-dark cycle, such as 12 hours of light and 12 hours of dark. Day glow or fluorescent bulbs should be off at night, but special nighttime bulbs can be used if desired.
- Lighting hood: Use a reptile heating/lighting hood over the tank to add lighting. These hoods have two ceramic receptacles for incandescent bulbs, allowing for a day glow bulb on one side and a night glow bulb on the other. Start with 15-watt bulbs, increasing wattage only if necessary, especially in a 10-gallon tank. Wood slats can raise the hood if it overheats the glass. Some hoods have a third receptacle for a fluorescent bulb; owners have reported success with Reptisun 2.0 fluorescent. Reptile heat hoods are best for glass top tanks or screens, though screens complicate humidity regulation and can melt if the lights get too hot.
- Don’t overheat the tank: Avoid desk lamps or high-wattage reptile bulbs, as they may overheat and excessively dry the tank.
How to set up a hermit Crab Tank (Properly!)
FAQ
How big of a tank for 1 hermit crab?
| Difficulty of Care | Beginner |
|---|---|
| Average Life Span | 10+ years with proper care, depending on species |
| Average Adult Size | 2–6 inches long, depending on species |
| Diet | Omnivorous |
| Minimum Habitat Size | 10-gallon glass tank for 1 or 2 hermit crabs |
How big of an enclosure should hermit crabs have?
Hermit crabs can be housed in either a glass or plastic tank. Choose a 10-gallon aquarium with a lid. A sliding glass lid works well to retain humidity. Small plastic homes sold as hermit crab kits are usually too small but are excellent for temporary housing or isolation.
Is it better to have 1 or 2 hermit crabs?
You shouldn’t put any more than 2 hermit crabs in it. If you want more hermit crabs, you’ll need to get a bigger tank.
How many hermit crabs for a 20 gallon tank?
A 20-gallon tank is generally suitable for two to three small to medium hermit crabs. It’s recommended to have at least 5 gallons of space per crab, and even more as they grow, according to the Hermit Crab Association.
How big should a hermit crab tank be?
Your hermit crab’s tank should be at least 30 gallons (110 L) if the crabs are medium-sized. However, if you just have a couple of very small crabs, then you can start with a 10 US gal (38 L) tank and upgrade as the crabs grow. This size tank will ensure that the crabs have plenty of room to play.
How many hermit crabs in a 5 gallon tank?
A 5 gallon tank is too small for hermit crabs. But if you are just starting out and will upgrade as soon as possible, you can temporarily house 2 hermit crabs in a 5 gallon tank. You can house around 10-12 hermit crabs in a 30-gallon tank. However, the more space for each hermit crab = the better.
How do I set up a tank for my hermit crab?
When setting up a tank for your hermit crab, there are several factors to consider to provide them with a comfortable and safe environment. The size of the tank is crucial for the well-being of your hermit crab. As a general rule, a tank should provide at least 5 gallons of space per hermit crab.