Hermit crabs are born in saltwater surroundings, and even terrestrial hermit crabs start life as aquatic zoea evolves into crustaceans. So, all captive hermit crabs need saltwater.
To prepare saltwater for hermit crabs, you must add marine salt to a gallon of clean, filtered water. Alternatively, you can make saltwater by mixing half a cup (4oz) of sea salt with a gallon of clean water. Never use table salt in water for hermit crabs because it contains traces of iodine.
Don’t take it away even if you never see your land hermit crabs using saltwater, as they’ll be bathing in and drinking it. A safe, steady supply of saltwater is the cornerstone of hermit crab care.
Do Hermit Crabs Need Saltwater?
All hermit crabs need a combination of saltwater and freshwater. Even hermit crabs from freshwater areas flourish in saltwater, which applies to land-dwelling hermit crabs and aquatic hermit crabs.
Unless a hermit crab was born in captivity, which is rare, it started life in the sea. Hermit crabs rarely breed when not in the wild, making it almost certain that your hermit crab needs saltwater.
Naturally, there are some key differences in the water needs of hermit crabs. Never place a hermit crab in a water tank if it’s not a marine lifeform.
If you keep marine hermit crabs in an underwater aquarium, you’ll still need to manage the saltwater supply. Equally, if your hermit crabs live with fish, these tankmates must be able to survive in saltwater.
Aquatic Hermit Crabs
As 7 of the 8 core genera of hermit crabs live underwater, aquatic hermit crabs are common pets. Many marine enthusiasts keep them in fish tanks, as hermit crabs keep a tank clean by eating algae and waste.
If the hermit crab is used to living in a saltwater environment, it must be kept in similar surroundings. This involves matching the temperature of the hermit crab’s native terrain. Anything too warm will cause stress, and hermit crabs die when too cold.
Of equal importance is maintaining the pH of your hermit crab tank. Salty seawater has a pH between 7.5 to 8.4. To be safe, avoid letting the pH of the tank water drop below 8.0 and don’t exceed 8.4.
Saltwater hermit crabs must live in salty water. As per The Great Basin Naturalist, filtering chemicals from freshwater without adding salt can cause irreparable damage.
Terrestrial Hermit Crabs
As mentioned, terrestrial hermit crabs don’t swim in the water as they evolved to live on dry land. Their bodies have small lungs, so hermit crabs risk drowning if left in water for a prolonged period.
All the same, land hermit crabs like to drink and bathe in saltwater. As per PLOS One, saltwater’s smell arouses hermit crabs’ senses. Around saltwater, hermit crabs have a keen sense of smell, which helps them locate food and threats.
Terrestrial hermit crabs should have two water sources: freshwater and saltwater. You can use freshwater as a base and add salt to create the latter.
Provide a saltwater bath for hermit crabs. This must be deep enough for the hermit crabs to submerge themselves but not so deep they can’t escape. You may need separate baths or tanks if there are significant size discrepancies between your hermit crabs.
Saltwater bathing helps hermit crabs imitate their natural environment. It also keeps the skin and shell moist, encouraging and enabling molting. Saltwater also kills gnat infestations.
What Happens if Hermit Crabs Lack Saltwater?
This depends on the breed of the hermit crab, as some can survive exclusively in a freshwater environment. Caribbean land hermits are the most common example of freshwater hermit crabs.
If you bought your hermit crabs in the United States, they need saltwater.
Hermit crabs denied saltwater grow distressed. They may initially struggle to adapt to life in captivity anyway, but the absence of saltwater will compound this anxiety. Remember, hermit crabs rely upon saltwater to stimulate their senses.
It’ll also prevent hermit crabs from mating. This isn’t a significant problem because captive hermit crabs rarely mate anyway. So, no access to saltwater reduces the chance of this to zero.
More importantly, hermit crabs without saltwater will be unable to molt. Saltwater moistens the interior of a shell, which encourages hermit crabs to burrow under the substrate and molt. If hermit crabs don’t molt, they grow too large for their exoskeleton and shell, so some become trapped in their shell.
If your hermit crabs knock over their saltwater dish or bath, they won’t die overnight.
Acquiring Saltwater for Hermit Crabs
Having established that hermit crabs need saltwater, you must provide it for your pets. You can purchase pre-mixed salt designed for marine life or create your own.
The latter is cheaper but can also carry more risk. We’ll explain the process of mixing saltwater shortly, but you’ll need to be precise with your ingredients and measurements.
You’ll find marine salt in most pet stores, especially fish specialists, or on a marine life website.
Marine salt will effortlessly replicate the saliency of the ocean. This will be particularly important to aquatic hermit crabs, as using marine salt will help them feel at home and adapt faster.
This doesn’t mean that marine salt can right other wrongs. Distilled water for hermit crabs, whether aquatic or terrestrial, remains a must.
As per Ecotoxicology and Environmental Safety, the chlorine and heavy metals found in tap water are lethal to hermit crabs. No amount of salt will change that fact.
As the name suggests, marine salt is extracted from natural water sources and contains everything that hermit crabs need to flourish. Even if your hermit crabs are terrestrial, they’ll enjoy drinking and bathing in water sprinkled with marine salt.
Pre-purchased marine salt will maintain the exact pH that hermit crabs need.
Too often, hermit crabs don’t exhibit any signs of ill health from unbalanced pH until it’s too late. Using specialist marine salt reduces the risks to your hermit crab’s health.
Instant Ocean Sea Salt for Hermit Crabs
Instant Ocean is the market leader for aquarium salt, largely due to its price point. In this instance, cheap doesn’t mean that it’s substandard, as it’s a quality sea salt used by many public aquariums.
If you pick up a 200-gallon box, you won’t need to restock for a while. The salt is entirely natural, with no traces of nitrates or phosphates. It can dissolve slowly, so be patient while preparing it.
If your hermit crabs take to this marine salt, consider upgrading them to crystals from the same brand. These cost more but contain additional calcium, which is essential to hermit crabs. Crystals will also offset any lingering, microscopic traces of heavy metals in water.
API Aquarium Salt for Hermit Crabs
This salt comes from API, one of the longest-standing and most reputable fish and exotic pet market brands. This means that you can trust the products.
Perhaps the main selling point is its medicinal qualities. API marine salt can resolve fungal infections and similar issues that can become a problem for hermit crabs. These are most likely if your hermit crabs are stressed and new to captivity.
Don’t rely on aquarium salt to single-handedly nurse hermit crabs back to health. If there’s an issue, you need to identify what caused it.
Jungle Aquarium Salt for Hermit Crabs
Bagged and sold by the pound, this brand of aquarium salt may be more expensive than some competitors, but it lives up to this price tag in performance.
This marine salt dissolves rapidly, so you’ll save time mixing and preparing saltwater. It also boasts numerous healing qualities for small wounds, such as nips from claws.
Because this salt is sold in smaller quantities, it’s ideal for land hermit crabs. Add a pinch to the drinking and bathing water. The bag will last a while, and your hermit crabs will benefit.
Purchasing salt for an aquarium may not be for everybody, so it may seem like a needless expense. After all, the average kitchen cupboard has plenty of salt.
Unfortunately, table salt is unsuitable for a hermit crab’s aquarium. Whether you’re making drinking water or a bath, table salt contains chemicals and ingredients that make hermit crabs sick.
Making saltwater is okay, especially if you keep terrestrial hermit crabs.
Can I Use Sea Salt to Make Saltwater for Hermit Crabs?
Table salt isn’t suitable for hermit crabs due to the iodine in table salt, which is toxic to hermit crabs. Also, many table salt brands apply anti-caking agents to the condiment to prevent clumping.
You can use pure sea salt from a supermarket, but ensure the salt is pure and unamended. For example, bath salts may have been chemically treated for aesthetic or scented appeal.
To be safe, consider getting your sea salt from a health food store. This may be slightly more expensive than the shelves of a supermarket, but it’s more likely to meet the needs of hermit crabs.
How to Mix Saltwater for Hermit Crabs
Once you have the right salt, you can mix your saltwater solution. Create saltwater by the gallon to control measurements. If you keep terrestrial crabs, one mix should be more than ample. If your hermit crabs are aquatic, you’ll need to repeat the process several times. The tools for mixing saltwater are:
- A vessel to hold the water
- Appropriate salt
- One gallon of filtered or bottled water – tap water is fatal to hermit crabs.
- Water conditioner – required if you are filling an aquarium for marine hermit crabs.
Line up your materials and start the mixing process:
- Clean your empty vessel, ensuring it contains no lingering chemicals or residue.
- Pour the water into your vessel.
- Add the water conditioner, if applicable, and stir thoroughly.
- Add half a cup of salt to the water.
- Stir the salt until the water is no longer cloudy and there are no lumps.
- Leave the water to sit and settle, ensuring it’s at room temperature.
- Apply the water to an aquarium or bathing and drinking dishes.
If your hermit crabs show any changes in behavior, switch back to branded marine salt.
Sea Salt to Water Ratio for Hermit Crabs
Apply half a cup of sea salt to one gallon of water. If you’re weighing salt rather than measuring it, tip the scales at 4oz. If you get marine salt, follow the instructions on the packaging.
You must follow these measurements, as the risks of insufficient salt in water have been profiled already. It’s just as harmful to have too much salt as an imbalanced pH in water can dry out the skin.
You’ll know if the water contains too much salt as it’ll be excessively cloudy. If you exceed the recommended amount of salt, cut the mix with freshwater.
If you remain concerned about the safety of your hermit crabs, get a hydrometer to measure the salinity of the water. It won’t be of much use for bathing water used by land hermit crabs. For aquatic animals, a hydrometer will keep them safe.
Saltwater is essential for all hermit crabs, and it must be mixed safely. If you’re not confident about mixing saltwater, get it directly from a pet store.