Do Hermit Crabs Need Saltwater?

Hermit crabs are fascinating and charming pets, and it is no wonder they have become so popular in households across the world. These crustaceans are known for carrying and switching shells, and they are captivating to watch. But when it comes to providing a suitable environment for hermit crabs, a common question is “Do hermit crabs need saltwater?” In this blog post, we will explore the importance of saltwater in hermit crab habitats and how to properly set up and maintain saltwater pools for your beloved pets.

Understanding Hermit Crab Species

First, we should distinguish between different types of hermit crabs. Marine hermit crabs are saltwater crustaceans that live in oceans and seas. Whereas, land hermit crabs, which belong to the genus Coenobita, live in tropical and subtropical regions that require a combination of land and saltwater environments to thrive. For the purpose of this blog post, we will focus primarily on semiterrestrial hermit crab species, such as the Ecuadorian and Caribbean hermit crab, which need saltwater to survive.

The Importance of Saltwater in Hermit Crab Habitats

Why is saltwater crucial to the health and well-being of hermit crabs? There are several reasons:

Osmoregulation and Hydration

Hermit crabs regulate their body fluids with saltwater, which prevents dehydration and maintains overall health. Saltwater is crucial for their survival, and they require it regularly to stay hydrated.

Molting Process

Hermit crabs require a specific level of salinity to undergo the molting process. When hermit crabs molt, they shed their exoskeleton to grow, making molting a critical process for their survival.

Shell Change and Growth

The shell is an essential aspect of a hermit crab’s habitat and survival, and saltwater helps to keep the shell clean and healthy. As hermit crabs grow, they require larger shells, which they typically find in the saltwater.


Breeding in hermit crabs occurs in saltwater environments, where the females release eggs for fertilization. Proper salinity levels and environmental factors are crucial for sea hermit crabs to reproduce successfully.

Preparing Saltwater for Your Hermit Crabs

Now that we understand the importance of saltwater to hermit crabs let’s look at how to prepare it. It is crucial to differentiate between table salt and marine salt when choosing which one to use. Marine salt is designed specifically for aquatic animals and contains essential minerals that mimic the natural saltwater found in oceans and seas. Table salt contains additives that can harm the crabs.

For marine hermit crabs, it is recommended to mix one cup of marine salt per gallon of water to achieve the ideal salinity level. For land hermit crabs, the recommended ratio is approximately 1/4 to 1/2 cup of marine salt per gallon of water. It is imperative to use non-chlorinated water while mixing the saltwater.

Saltwater Pools in Hermit Crab Enclosures

The best way to provide saltwater for hermit crabs is by creating saltwater pools within their enclosure. The primary factors to keep in mind when constructing saltwater pools for your hermit crabs are:

Size and Depth of Pools

The size of the pool should be proportional to the size of your hermit crab. The depth of the pool should not exceed the height of the crab, and a small ramp or rocks should be placed for accessibility.

Container and Material Selection

The container holding the saltwater should be sturdy and made of plastic or glass. Avoid using metal containers that can rust and harm the crabs.

Accessibility for Hermit Crabs

Hermit crabs require gradual depth levels to climb and exit the pool. It is recommended to include items such as plastic plants, rocks, or coral to help the crabs climb.

Maintenance of Saltwater Pools

It is crucial to monitor the salinity level of the pool regularly and conduct regular cleaning to prevent the accumulation of harmful bacteria.

Freshwater in Hermit Crab Habitats

While saltwater is vital for crab survival, freshwater is equally important. Hermit crabs need to stay hydrated, and freshwater pools are an excellent source of drinking water. It is recommended to keep freshwater pools separate from saltwater pools to prevent contamination. Similar to saltwater pools, freshwater pools require daily maintenance to ensure the water is clean and non-chlorinated.

Additional Environmental Factors for Hermit Crab Care

Apart from providing saltwater and freshwater pools, there are other critical environmental factors to consider when caring for your hermit crabs. Substrate requirements, such as a mixture of coconut fiber and sand, provide a suitable environment for burrowing and molting. Heat lamps and heat mats are necessary to maintain the temperature and humidity levels required for hermit crabs. Nutritious food that contains protein, calcium, and vegetables, along with avoiding harmful ingredients, should be taken into account.


In conclusion, saltwater is an essential aspect of hermit crab habitats. It helps to regulate body fluids, aids the molting process, promotes shell health, and supports reproduction. Providing suitable saltwater pools is necessary to maintain your pet’s overall health and happiness. Proper preparation, maintenance, and monitoring are vital to ensure your hermit crabs thrive in their environment. By keeping all environmental factors in mind, you can enjoy watching your hermit crabs grow and thrive in a healthy and sustainable environment.