The Crab Street Journal FAQs

The importance of the right kind of salt

written by Jennifer Nielsen

Freshwater aquarium salt is not the same as marine or ocean salt

Freshwater aquarium salt is not the same as marine or ocean salt

The existence of an ocean water dish is a source of great controversy in the world of hermit crab owners. Why the importance of this type of water is rarely debated, it seems that the products used in the creation of Ocean Water are the source of much debate. Just as all hermit crab owners know not to use table salt for their crabs, there are two types of salt available for aquarium use. Fresh Saltwater as well as Ocean Water Salt, which although made of the same components have vastly different role within the world of fish keeping.

A saltwater dish is offered as a means for hermit crabs in captivity to gain access to the ocean with in the habitat. In the wild, a hermit crab would normally crawl down to the sea side to get sea water to help balance the ph/ion levels within their shells. However, in the man-created environment within the habitat, this cannot happen unless a human is providing this type of water. The product used to create this water is of critical importance for this reason, plus in case of injury, salt water is also naturally defecting that will assist in healing of wounds. Hermit Crabs have been known to be seen soaking an injured claw within the salt water pond. Also, molts tend to go a better in the habitats where salt water is readily available.

In order to understand the difference in the product lines, we need to see what Natural Sea Water (NSW) is composed of. The first ingredient is salt of course. However, it also contains about 70 other trace chemicals within it. So while the primary ingredient is in fact common salt (NaCl) there is also several other elements which are key to the composition of Ocean Water. The major components in addition to Chlorine and Sodium are Magnesium, Sulfur/Sulphur, Calcium, and Potassium. Also, common minor components are Bicarbonate, Bromine, Strontium and Silicon. These are considered to be essential to the creation of artificial salt water. This is in addition to other elements, which are in lower amount but found in NSW, such as Chromium, Cobalt, Copper, Fluorine/Fluoride, Iodine/Iodide, Iron, Manganese, Molybdenum, Nickel, Phosphorus/Phosphate, Selenium, Tin, Vanadium and Zinc. Also it is important to note that in the creation of artificial ocean water mixes also tend to be over in Nitrogen/Hydrogen, Nitrate-Nitrogen, Phosphorus as well as Silcon. So offering just one of these elements, such as just the salt, is not truly providing a Salt Water, for several ingredients are missing from the equation.

Now, this is not to say that the salinity level found around the world is stable. Factors such as weather, heat, and location are also factors in the composition of salt water. The Dead Sea is in fact the saltiest body of water in the world. Water located around the equator is also saltier than that which is found in the arctic. While this could be important to different varieties of Hermit Crabs, that is a subject for more research to find out which products mimic different water conditions world wide.

Ocean or Marine salt is required by hermit crabs

Ocean or Marine salt is required by hermit crabs

Freshwater Salt is designed to primarily be a treatment of illness in fish. Specifically, freshwater fish can tolerate low slowly introduced salt in their water. Natural Freshwater does contain salt, but compared to the amounts found in NSW water, the volume of this is significantly lower. Products designed with only this purpose in mind, tend to lack the other elements found in Sea Water. The same is true for cooking salt made from evaporated ocean water. For while the salt is sea salt, it is lacking the other components that make ocean water what it is.

Ocean Water salts, however, provide not only the salt needed but the other components as well. In fact, the label Ocean Water mixes might be a better term for these products because of the fact that they are not just containing one part of the water, but a variety of components that are found in NSW. For the Aquarist who keeps salt water tanks, this is of critical importance to their pets. Therefore, they tend to go with mixes that are more than just salt. In trying to offer Hermit Crabs ocean ponds, it is important that a mix with true composition closest to NSW is used which is why ocean water salt is preferred over Freshwater Salt.

Websites used to provide information in this article are:

Gore on Salinity
Dead Link-Page not Found See archive of webpage here.
Sea Salt mixes

Brands of salt to look for:

  1. Instant Ocean/Instant Ocean Reef Crystals
  2. Oceanic
  3. Red Sea Salt
  4. Fluval Sea Salt
  5. Coralife
  6. Tetra Marine

FAQ A Close Look At Salt Products

Hermit crab enthusiast Jennifer Nielsen compares several brands of sea salt mix in this article.

Instant Ocean and Oceanic Salt Mix for hermit crabs

A comparison of several brands of sea salt mix

Written by Jennifer Nielsen (aka redjln)

While many hermit crab owners realize the importance of providing Ocean Water to their pets, there is a question over which type and which specific product is the best. To answer this, I got Instant Ocean and Reef Crystals enriched blend by Aquarium Systems, Doc Wellfish’s Aquarium Salt, and Aquarium Salt by Jungle. I have gotten a container of Distilled Water to test the products in.

Now, I will disclaim right now that I do not have access to a laboratory of equipment. All I have to test with is a test kit by the name of Marine Master Saltwater test kit. This test kit was not the most expensive, not the cheapest. The test kit can test for pH, Nitrite, Ammonia, and Nitrate. Nitrate/Nitrite is both forms of Nitrogen that is on its way to be coming ammonia. Too much of both of these are deadly to both humans and animals, but are the final stages of the breakdown of waste products from living things. This is a critical part of marine fish keeping, and which is why it was included in the test kit. However for the sake of Hermit Crabs which consume the water, and the fact that nothing is living in this water, testing for pH is the only test that is logical.

What pH is defined as is a measurement of the concentration of hydrogen and hydroxide ions, as well as measures how acidic or alkaline it is. The scale ranges from zero to fourteen. Seven is the ideal number for that is neutral. Less than seven is an acidic solution, and greater than seven is alkaline solution. A good ocean water mix should have between 8.0 and 8.3 pH as that is what the ocean’s pH is. For the sake of this test, I am using this as means to discover if anything else is present in any of the waters.

I also got an inexpensive hydrometer for this testing. What a hydrometer is a means of measuring the amount of salt in water. Natural Sea Water is about 3.5%, yet this is affected by a variety of factors including water temperature. According to my research, marine tank owners tend to want their salinity to be between 1.021-1.024 and since the marine tank owners animals live in imitation ocean water I defer to the range that believe to be best. It has to be tested within a container that allows for the meter to float, which with it being a rather long glass tube posed it own challenges. Eventually I found containers that would work and they were boiled to sterilize them.

For a truly fair test, I decide to use distilled water. Distilled water is water that has no additives in it. Unlike tap or well water which will have minerals or other items in it which I figured could effect the results, I decided to go with as pure of water that I could find.

The first thing about The Doc Wellfish and Jungle products is terms such as “General Tonic and Stress reducers” or “Tropical Fish Treatment or with a remedy” on the packages. The Jungle product even gives a nice set of instructions on how to use this product to clean the tank. Neither the Jungle nor Doc Wellfish products truly give a method of creating ocean water. Which is what the hermit crabs are in of needed. Now the Instant Ocean product just explains that it comes close to being a natural ocean environment. Crystal Reefs also makes the same claims, but that their product also has added calcium.

The looks of the products vary. Doc Wellfish salt is shaped like large crystals. The Jungle Product has smaller crystal. However the Crystal Reef product has tiny crystals and Instant Ocean is a powder. From the standpoint of having to dissolve these products, Instant Ocean would appear to be the easiest to do so with. However, it turns out that all the salts were quickly and easily dissolved, Doc Wellfish only requiring a bit more stirring than the other products in the distilled water.

Now, both Instant Ocean and Reef Crystals give the instructions of a half cup to a gallon of water. There are sixteen cups in a gallon. There sixteen tablespoons in a cup, which meaning eight tablespoons in a half cup. Also there is a ratio of three teaspoons per tablespoon. Now to make a cup of ocean water with these products, I worked out that sixteen cups of water divided by twenty four teaspoons equals about one and half teaspoons. For a cup of water, I would need to use one and a half teaspoons. Now for the Jungle Salt and Doc Wellfish, I figured out that the directions of one tablespoon per five gallons worked out to about less than one-tenth of a teaspoon per cup. Plus, the ratios seemed a bit small, that I was not sure my hydrometer would be able to trace it. So I decided that one quarter of a teaspoon to four cups of water would have to work.

Then containers with the mixtures would also be given a chance to sit overnight to give the salt time to mend with the water and measurements taken. Although the packages claimed that the water would to be pretty much ready to use right away. My research suggested that allowing the water to rest prior to use. Also considering the amounts that most hermit crab owners use, any effects of the ocean water sitting would have an effect. This would show what the levels as if they water had been sitting for a bit. I know that with my thirteen hermit crabs it takes about a week to go through one cup of water.

The first test results were interesting taken after about an hour from the time the water was created. Instant Ocean landed in the center of the 1.020 to 1.030 range. Crystal Reef measured 1.034 to 1.036 ranges. This is higher than the preferred range for salt. Jungle’s salt, in spite of the ratio being higher than what the packaged suggested turned out to be ranking very low salt content of 1.000. Which when I tested my drinking water, is the same amount of this. Doc Wellfish tested to be 1.002. The next day, the hydrometer show no results when I tested the Jungle water. However, the Instant Ocean and Crystal Reef stayed the same with regards to the results I had gotten the day before. I waited a few more days and tried again. The result with Crystal Reef had changed, for the salt level had stabilized within the proper range after four days.

The pH test worked my changing the Ocean Water color. Instant Ocean and Crystal Reef measured a pH of 8.0 after creation and remained stable at this for the next few days. I could not get a reading for the Fresh Water Salt products. They had less than 7.8 pH content in it. The pH for Doc WellFish continued to decrease as well as for the Jungle Product, as I could tell by the color, but was not able to measure with my kit.

I would say the besides the fact the Ocean Water Mixes designed for Marine Tanks do contain more items in it than the products designed for Freshwater tanks. That the fresh water products would require a lot more salt than their packages suggest to create ocean water and are also missing the “something” that cause the pH in the marine products to stabilize. The Jungle Salt even breaks down to not even being in measurable in the water. The fact that Instant Ocean was within range for everything from the start it might be the preferred product to use. Yet, Crystal Reefs could be modified with the addition of some more fresh water to fall within the proper range. However, after sitting four days, it came into range on its own. If I had added the water would have made it back out of range for being too low in salinity.

The main conclusion I came to was that there is something different about the products that are used/designed for Marine Tanks. Something is present in the water that makes the pH stay stable and not decrease. For this reason alone, I advise that people use a Marine Salt mixture, and since most people may not have access to a hydrometer, mix the mixture light so as not to burn the hermit’s gills with too salty of water, considering that tap water also might contain a trace of salt in it.

For further information regarding freshwater salt mixes vs. ocean/sea water mixes that has been recently discovered, please see the end of Ocean Mixes at:
How do I mix ocean water

FAQ How do I mix ocean water?

Special credit thanks to Wendy at Hermit Crabs R Us for compiling and sharing this list!!

After mixing all ocean/sea mixes leave sit for at least 12-24 hours prior to offering to ensure that all the crystals have dissolved.

Ocean or Marine salt is required by hermit crabs

Ocean or Marine salt is required by hermit crabs

Crystal Sea Marine mix Bioassy Formula
The site from which I purchased this mix indicates 1/4 lb or 1/3 cup will yield 1 gallon. I found it to only be 1.016 SG when mixed this way. I tested it using 2 different hydrometers-one that was also purchased at the same site as the salt mix. I mixed it using 1/2 cup and got 1.021. (I add an additional tablespoon for my C. Perlatus to raise it 1.023)
* 1 1/2 tsp per 8 oz (1 cup) water
* 1 TBSP per 16 oz (1 pint)
* 2 TBSP per 32 oz (1 quart)
* 4 TBSP per 64 oz (1/2 gallon)
* 8 TBSP per 128 oz (1 gallon)

Instant Ocean
The package indicates to use 1/2 cup (which=8 TBSP) per gallon.
* 1 1/2 tsp per 8 oz (1 cup) water
* 1 TBSP per 16 oz (1 pint)
* 2 TBSP per 32 oz (1 quart)
* 4 TBSP per 64 oz (1/2 gallon)
* 8 TBSP per 128 oz (1 gallon)

Oceanic Natural Sea Salt Mix
The package to make 5 gallons indicates .29 lbs/gallon. I measured the package and it was approximately 2 1/2 cups. Which is 1/2 cup per gallon or 8 TBSP
* 1 1/2 tsp per 8 oz (1 cup) water
* 1 TBSP per 16 oz (1 pint)
* 2 TBSP per 32 oz (1 quart)
* 4 TBSP per 64 oz (1/2 gallon)
* 8 TBSP per 128 oz (1 gallon)

* This is the salt I am currently using and 8 TBSP makes a specific gravity of 1.021. I use an additional tablespoon to raise the specific gravity for my C. Perlatus. I also provide Doc Wellfish crystals in the food dish as well.

Red Sea Salt
The package directions indicate 2.8 lbs. dissolved in 10 US gallons, which is .28 lbs for 1 lb which again is basically the same as Oceanic 1/2 cup per gallon (or 8 TBSP)
* 1 1/2 tsp per 8 oz (1 cup) water
* 1 TBSP per 16 oz (1 pint)
* 2 TBSP per 32 oz (1 quart)
* 4 TBSP per 64 oz (1/2 gallon)
* 8 TBSP per 128 oz (1 gallon)

Tropic Marin Sea Salt
The package instructions indicate 151 grams = 1 gallon. 151gms x .0353 = 5.33 ounces.
5.33oz/8(oz in a cup) = .66 or 2/3 cup per gallon. There are 31.68 or 32 tsp in 2/3 of a cup.
* 2 tsp per 8 oz (1 cup) water
* 4 tsp ( 1TBSP+1tsp) per 16 oz (1 pint)
* 8 tsp ( 2TBSP+2tsp) per 32 oz (1 quart)
* 16 tsp ( 5TBSP+1tsp) per 64 oz (1/2 gallon)
* 32 tsp (10TBSP+2tsp) per 128 oz (1 gallon)

So basically all of the dry salt mixes tend to be 1/2 cup or 8 TBSP per gallon of water. If you are unsure if your sea water is salty enough or too salty you can purchase a hydrometer which measures specific gravity. The specific gravity of sea water varies depending on location, but is generally somewhere between 1.020 and 1.025. To get an accurate result with your hygrometer, the water should be around 77 degrees Fahrenheit.

If you are offering both a de-chlorinated fresh water dish as well as a de-chlorinated salt water dish, you needn’t worry if the mix is too salty. The crabs can adjust their shell water accordingly. If you have C. Perlatus, saltier water is more beneficial as their shell water has been shown to be much higher in salt content than those of other species.
In addition, if the salt water dish is not salty enough, they will need to obtain natural sea salt from other sources such as their diet. One option is to provide a small pile of the Sea salt crystals with their food.

Here is some additional reading about specific gravity (versus salinity)

Saltwater Salinity and Specific Gravity


* CUP tsp TBSP
* ¼————–12——–4
* ½————–24——–8
* 1————–48——–16
* 2————–96——–32

* How many ounces in a:
* 8 cup
* 16 pint
* 32 quart
* 64 1/2 gallon
* 128 Gallon

Conversion Table

Additional information added to Wendy’s compiled Ocean mix, by Marie (aka ladybug15057)

Both the ZooMed Part 2 and HBH hermit crab salt mixes were tested for salinity levels. If mixed per the products instructions, they do not register a salinity level on a hydrometer. Land hermit crabs should be offered an ocean/sea water pond with a salinity level of 1.021-1.024.

ZooMed Part 2 has a yellow dye within it, something a hermit crab does not need within their diet. Within this product, it does not contain an ingredient to remove heavy metals from tap water, as well as ZooMed Part 1 fresh water conditioner does not contain a heavy metal neutralizer.

HBH Hermit crab sea salt Ingredients: sodium chloride, magnesium chloride, calcium chloride, potassium chloride, potassium iodide
It contains the wrong form of calcium and it contains normal table salt ingredients sodium chloride/ potassium iodide. HBH salt mix also contains a highly corrosive magnesium chloride that is used to stabilize the iodine. (Thanks to SUE, RFCrabs for this information regarding HBH salt mix)

It is not known for fact whether either of these Salt mixes for hermit crabs are made with freshwater salt mix or ocean/sea water mix. This includes the Glub Salt water sold for hermit crabs.

Ocean/sea water elements are different than those of freshwater. Hermit crabs need the elements that are found in ocean/sea water to remain healthy:

(Please see attached file bottom right of this page- file is missing!)

This information regarding Epson salt was shared with Marie (aka ladybug15057) by a zoologist/biologist who is responsible for the aquarium care at a zoo in Texas.

“Freshwater” salt mixes (such as Doc Wellfishes and API) mainly consist of Epsom Salt, which is an anesthetic for invertebrates and can easily kill them. To euthanize an invertebrate is usually done by overdosing it on anesthetic where normally Epsom salt is used. An Epsom salt bath will usually cause invertebrates to slowly go to sleep.

Related Links and Archived Links:

Advanced Aquarist Salt Mixes Part 1

Advance Aquarist Salt Mixes Part 2

Salinity GPC EDU

Saltwater Salinity and Specific Gravity Algone

Why is the Ocean Salty Palomar EDU

Sea Salt Mixes- About.com

FAQ Cost Cutting Tips

CuttingCostWritten by Travis Wease
Tips for saving money and having a safe crabitat:

First off there are certain things that you can’t really skimp on when it comes to setting up a safe and fun crabitat. Things like a heat source whether it be lights or a UTH, substrate has a cost, although some are cheaper, humidity gauges, temperature gauges, and the tank itself has a cost, but here are some tips to save money and use items that you may already have laying around the house.

1.Look on Craigslist or Freecycle for tanks. Sometimes you can find them at Goodwill or other re-use stores very cheap. Most Wal-Marts sell a 10 gallon tank for 10 dollars, and that is the smallest I would recommend to house Hermit Crabs in.

2.Hidey huts can be made out of a lot of things. You can use a coffee mug turned on its side, a small plastic cup, and what I like to use are small Terra Cotta pots used for plants. Another thought is to buy a coconut from the grocery store and break it in half. Once you have all the milk, and meat out of the coconut you can cut a hole in the half and have a homemade cocohut for your crabs as well as some food for them. Another thing you can make a hidey out of are Lego’s.

3.Decorations are the same way you can use a lot of things to decorate your tank. Silk plants can be used, if you happen to have an aquarium a lot of the decorations for an aquarium can be used in the tank as well. Dollar stores, or Wal-mart, or crafts stores often have hanging vines that can be used with suction cups to hang in the tank as well. Cholla wood can be found in stores as can be used for climbing and the crabs love it and are known to snack on it. Another thing I use is cuttlebone. I stick the whole piece in my tank and the crab can climb on it and it is great calcium for post molters, lava stones are popular as well.

4. Shells can be found at dollar stores, craft stores, Wal-mart, and many online stores a lot of time quite a bit cheaper than you will ever find in a pet store.

5.Food/Diet is one area that you definitely don’t want to neglect but it is also an area you can save money as well. A lot of the foods we eat can be given to the crab as long as no pesticides or preservatives or seasonings of any type have been used. Also no table salt should be used or offered. Many of the fruits and veggies though are great for the crabs and some of their favorites. There are many online stores that sell great food and products and are very reasonably priced and ran by some very good crabbers.

6.Dishes can be made out of just about anything. You can use large clam shells for food or even things like tops of jars like plastic peanut bar jars, small Tupperware bowls, and lids from Tupperware bowls as well.

These are just some areas meant to help save money but there are many others as well. If you know that you or your neighbors do not use pesticides on your yard you can get things from there as well. Oak and maple leaves are very popular with crabs, dandelions are another favorite. Barks from oak and maple trees are great as well. Roly poly bugs can be put in the tank to help keep the substrate clean and don’t bother the crabs. Dollar stores have various containers and baskets that can be used in crabitats for hidey huts and dishes, containers for substrate.

FAQ Locating an Escaped Hermit Crab

Written by Marie Davis

Ebbie the compressus climbed the thermometer

FAQ Locating an escaped hermit crab – Ebbie the compressus climbed the thermometer

On occasions one may find that when they do an antenna count they seem to be missing a hermit crab? Where possibly could it be? All empty shells have been looked into, including doing the precaution of turning the shells upside down and placing water within them. There have been occasions when a hermit crab has changed shells and fits so far down within it they are impossible to see. By placing water within the shells and turning them hole side up, if the shell moves hole side down a crabber knows there is a resident within it.

Could he be hiding that well in the crabitat? If one has looked within every tank item, including the little crevices some items have, as well as completely sifted through their substrate inch by inch there maybe a chance he has escaped. (Note: if you have other crabs don’t molting do not disturb your substrate)

Trooper AKA Spiderman

Trooper AKA Spiderman

Even if one feels this is impossible for the hermit crab to do because none of their crabitat items come close to the top of the tank, unless one has a screen lid to cover the top of the tank it is possible for the hermit crab to have escaped. They are expert climbers and are even capable of climbing the silicone on the inside of the tank corners.

Now the whole inside of the tank has been checked. Each item has been looked at inside including the holes of any and all logs and huts within the tank. The substrate has been gone through as well as all empty shells have been looked into. Hermit Crab count is still missing one.

Look around the outside of the tank, including around the legs of the stand the tank is on. Make sure to check all wiring around the tank and what maybe leading down from the tank. Check under couches, chairs, tables, beds, plants, along the wall of the room and other rooms close by. Check curtains, closets, within shoes, under refrigerators, in bathrooms or where it maybe warm and a bit humid. If you have other pets, check around the water and food dishes.

When it gets to be dusk, place newspaper or aluminum foil along the edges of the wall on the floor. Place some smelly food (eg. Sardines, shrimp, krill, tuna, etc) on the paper/foil as well as a water source. Sit quietly in a very dim room, or a dark room and listen carefully. It may also help if you have a flashlight handy so if you do hear a scooting across the paper/foil you will be able to turn it on and see where the sound is coming from. This method may take a couple of nights for one to find their hermit crab, so one does need to be patient.

A very determined perlatus climbed the silicon and began tearing open the screen lid

A very determined perlatus climbed the silicon and began tearing open the screen lid

A very determined perlatus climbed the silicon and began tearing open the screen lid

A very determined perlatus climbed the silicon and began tearing open the screen lid

Here are a few ideas/tips from other Crab Street Journal members:

Grant wrote:
I imagine you would want to consider their needs and plan from there:
Mine always head for dark areas

Remove all electrical wires from the floor and other things that can be used for climbing to make sure that they stay safely on the ground.

In the dark area(s) set up for them maybe place some food, maybe even a fan to provide a breeze to draw their attention to the area.

If you plan on hanging out and wait: set up some glasses or things that their shell will clank against.

Daethian wrote:
Grant in a research article I was reading last week or so about the amazing sense of smell of hermit crabs, the researchers actually set up large fans at night and the crabs consistently traveled away from the fans. Even when it meant they were travelling away from their home sea. Where without the fan blowing they tended to almost always naturally orient toward their home sea. They can definitely smell ocean water.

CtryLuv wrote:
here are the things I have listed on my site.

* Check dark, damp places, such as bathrooms, laundry rooms and closets. They will try to find a place where they feel safe and where there is more warmth and humidity than anywhere else in the house.

* Place a nice smelly food that your crabby enjoys out in the open. Place it on something such as wax paper, tin foil or paper so that when he crawls on it, you can hear him.

* If you have other animals watch them. Cats and dogs are very good at knowing when there is something around that isn’t there usually. If they seem to be sniffing around somewhere, or trying to get to an area they don’t normally go to, check it out.

* Also check under certain appliances such as refrigerator and washers. These are dark warm places hermies might like.

* Look up high. A lot of people have found their crabbies scaling curtains and drapes. Anything you have that they can climb, check it out.

Not sure if those are just repeats of others listed above, but these are things Ive picked up over the years. I’ve only had one escaped crabbie “Bob” and of course he was just strolling across house like he owned it, so he didn’t apply to any of the above, but Bob was a macho hermie, hehehehe.

FAQ What foods are good and bad for hermit crabs?

Hermit Crabs are beach scavengers and they can and will eat a wide range of things. General rules:

Photo by bird1234 (youtube)

FAQ What foods are good and bad for hermit crabs? – Coenobita perlatus eating garbage – Photo by bird1234 (youtube)

Avoid chemicals, pesticides, table salt, moldy foods, plants that are toxic to animals.

For hermit crab nutritional needs and the foods that provide them, download the nutritional food chart as a PDF by clicking in the gray box below.

Hermit Crab Nutrition Table
Hermit Crab Nutrition Table
270.6 KiB

Written by Kerie Campbell

Fruits – Fresh or Wrinkly? I’ve read alot about fresh fruits being in their diets, which I use alot of BTW. But I’ve read alot about people putting in fruits that are old and wrinkling up. Is one better than the other?

Answer by: Kerie
Posted: Fri Mar 04, 2005 7:52 am
The crabs like it fresh, and they like it wrinkled. Mine also like stuff that’s gone mushy from being thawed after freezing. Alternating fresh and older fruit is a good way to vary their diet. The sugars and other compounds like terpenoids in the fruit will tend to change composition and break down for different flavors as the fruit ages. If it’s citrus fruit, though, you should always let it sit until it is wrinkly. The peels contain substances like limonene that act as insect repellents. Limonene breaks down quickly in the fruit peel as it ages, so letting it go wrinkly makes it much more attractive to the crabs. Citrus has compounds in the pith and stringy stuff that are extremely beneficial to crabs, such as beta carotene, and so citrus should be offered them on occasion, in order to promote a healthy diet.

What foods are good for hermit crabs?

Almonds, crushed
Amaranth (Ancient grain – calcium)
Anchovy oil
Apple and natural, unsweetened apple sauce
Barley (calcium)
Bell peppers (red, yellow, orange, green or purple)
Bee pollen
Blackberry leaves
Bone Meal (no additives, preservatives, sold as a supplement for people)
Broccoli and leaves
Brown rice, soy, wheat or 7 grain cereal
Brown rice
Carnation flowers
Carrots (carotenoids)
Carrot tops (vit. E)
Cat Tails
Cauliflower and leaves
Celery leaves
Chamomile flowers
Chicken bones
Chicken, cooked and unseasoned (smash the bone for marrow access)
Cholla wood
Clover blossoms and leaves
Coconut and coconut oil
Cod liver oil
Collards (calcium)
Cooked eggs
Cork bark
Corn (on the cob, too)
Cranberries (dehydrated)
Cuttlefish bone, powdered
Dandelion flowers, leaves and roots
Egg, scrambled or soft boiled
Extra-virgin olive oil
Fish flakes w/out chemical preservatives
Fish Oil
Flax seeds (crushed)
Flax seed oil (small amounts infrequently)
Frozen fish food (esp. algae, krill and brine shrimp)
Garbanzos (calcium)
Grape Leaf
Grapevine (vines and root)
Green and red leaf lettuce (not iceburg; dark green)
Green Beans
Hempseed Meal
Hibiscus flowers
Hikari products: brine shrimp, krill, crab cuisine, sea plankton (no preservatives, ethoxyquin, copper sulfate)
Hollyhock flowers
Honey (organic, or at least locally produced, for anti-microbials)
Honeydew Melon
Irish Moss
Impatiens flowers
Jasmine flowers
Kelp (calcium)
Lobster with crushed exoskeleton
Marigold flowers (calendula)
Marion Berries
Mint (but not peppermint!)
Most organic baby foods
Mulberry (fruit, leaves, wood)
Nasturtium flowers
Nettle (wilted)
Oak Leaves and bark
Olive and olive oil (extra virgin)
Oysters (zinc)
Pansy flowers and leaves
Parsley (calcium & vit. C)
Peanut butter (avoid sugar, corn syrup and hydrogenated oils)
Pecan bark
Plain calcium carbonate powder
Popcorn (unseasoned, unflavored, unbuttered)
Potato (no green parts, including eyes)
Quinoa (New World grain – calcium)
Raisins (no sulphur dioxide)
Red raspberry leaves (highest bio available calcium source + vit. C and trace minerals)
Rolled Oats
Rose petals
Rose hips (high in Vit. C)
Royal Jelly
Sand dollars
Sardines (calcium)
Sea biscuits
Sea fan (red or black)
Sea grasses
Sea salt
Sea Sponges
Sesame seeds (crushed)
Shrimp and exoskeletons
Spirulina (complete protein and chlorophyll source; highest in beta carotene)
Sprouts (flax, wheat, bean, alfalfa, etc.)
Squash and blossoms
Strawberry and tops
Sunflower Seeds (crushed), flowers and leaves
Swamp cypress wood (false cypress, taxodium sp.)
Sweet potato
Tuna (zinc)
Turnip greens (calcium)
Violet flowers
Wasa All-Natural? Crispbread (Oat flavor)
Watercress (vit. A)
Wheat grass (magnesium)
Wheat (calcium)
Wheat germ (B vitamins)
Whole Wheat Couscous
Worm Castings

Other herb flowers-The tiny flowering blooms of the following spices are edible: anise, basil, bee balm, chives, coriander (cilantro), dill, fennel, garlic, oregano, rosemary, and thyme.


Beetle Grubs
Cicada exo skeletons
Feeder cockroaches
Super worms

* This food list is mainly adapted from Summer Michealson and Stacey Arenella’s book, The All-Natural? Hermit Crab Sourcebook, and expanded on by Julia Crab and others

What foods are bad for hermit crabs?

While it is true that crabs are scavengers with a wide repertoire of foods they can eat, there are many plants and foods that just should not be fed to a crab. The foods on this list are to be avoided. Some are toxic, some are insect repellents or used as insecticides, and some the crabs just won’t go near, such as lemon — lemon won’t hurt them, but they certainly won’t eat it.

Aconite (Monk’s Hood)
African violet leaves
Alder bark
Aloe vera (interferes with potassium absorption)
American Hellebore
Avocado leaves
Bird of Paradise Flowers
Bottlebrush flowers
Carnation leaves
Castor Bean
Cherimoya Seeds
Citrus (leaves and branches to be avoided; part of the evergreen family. The fruit is fine)
Compost (unless 100% organic)
Crown of Thorns
Cube Plant
Custard Apple (young fruit)
European pennyroyal
Evergreen (pine, cedar, juniper, etc.)
Golden Pothos
Green hellebore
Holly Berries
Ivy (of any kind)
Juniper Berries
Larkspur seed
Lemon Balm (Sweet Melissa)
Lemon Grass
Lucky Bamboo (Dracaena sanderiana)
Morning Glory
Oxeye daisy
Papaya seed
Parsley Seed (fruit)
Peace Lily
Pencil Tree Cactus
Pine or cedar wood or needles
Prickly juniper
Pride of China fruit
Prunus species trees (apricot, bitter almond, cherry, cherry laurel,
nectarine, peach, plum) Fleshy fruits are edible, everything else
contains a cyanide-like compound and is fatally toxic, including
seeds, wood, leaves, bark and flowers.
Red Emerald
Sago Palm
Stargazer Lily (Lilium x Stargazer)
Sweet Flag
Tea Tree
Texas Mountain Laurel (Sophora secundiflora)
Wild Angelica fruit

From: The San Diego Turtle and Tortoise Society
And other sources

We highly recommend keeping worm castings and greensand on hand and in your tank daily. Both are highly nutritious and are loved by hermit crabs.

Awesome video of a huge  gathering of Coenobita perlatus eating garbage

FAQ How do I get the stink out of a shell?

FAQ How do I get the smell out of an empty sea shell so I can reuse it?

FAQ How do I get the smell out of an empty sea shell so I can reuse it?

CrabbyMum asked:

Get the odor out of shells? I know to boil newly purchased shells, but I want to reuse some of the shells that are smelly from a crab dying in it. So far, we’ve lost one of the Littles (PP = Faith) and I think another is not going to make it. I have her in iso and will wait til we are sure before dealing with it’s shell tho. But I tried soaking the ones that Violet and Faith were in because the odor was so strong in them yet and then boiled them. I remember reading how Vinegar can damage them so I didn’t use anything but declorinated water. Didn’t dare try soap or dishwashing liquid either. But once the water got to boiling the odor nearly drove us all out of the house. :sick: What should I have done? Is there a safe way to remove the odor?
I really want to get these shells clean because they are both usable shells. Violet’s was large and not particularly pretty on the outside, but the inside is in good condition except for the odor. Faith’s is painted and boiling removed most of the paint and the clear shellac or what ever the polish was on it. The size of that one is perfect for the other Little one and since I don’t have much in the way of tiny shells (waiting for a new order to get here), I really need it before she comes up from destressing. At least I HOPE that is why she is still in hiding…

are you boiling with SALT water?

I just had a crazy thought that might safely work….ocean water will probably eat away the shine of the shell if there is any. But put some ocean water within the shell and leave it sit for a couple of hours. Shake out the ocean water, and here is the crazy part…put it in a baggy with a twisty tie on it and place it in the freezer overnight. Not sure if you have ever heard of it or tried it, (and it works too….if one has a smelly pair of tenny shoes, (or any shoes) and put them in a garbage bag and put them in the freezer for 24 hours it kills the stench of the shoes. Honest…it works with shoes.

Hmmm… Hadn’t thought of using salt in the water. Just declorinated and boiled about 5 minutes. I was tempted to try a weak bleach solution but was afraid of what that might do to the shell and didn’t want to risk not being able to get it all out of the shell. I would think that a crab with a bleached bottom would be crabby indeed. :blush:
I like the baking soda and/or lemon idea as they are natural and are natural deodorizers. Faith’s shell is a shiny spotted one (looks to be a Babylon Spirata type) so I’d like to preserve it if possible. Violet’s shell is a nonpolished Pica and the outside is sort of crusted with a stone like material that I was afraid would come off when it was cleaned – but it didn’t.
Marie. Oh golly – I remember doing that with tennies when I was a girl. It really did kill alot of odors – we soaked them in baking soda water, froze them in the snowbanks in winter and then left them hanging on a line for a day or two. I’ll give it a try with the soda and the freezer.

Ok – I wonder… How about soaking in Hydrogen Peroxide? Just in case the odor is still there because there is something still stuck inside the shell that I can’t get at. Wouldn’t that bubble it out?

I was a bit leery to post this link last night, but if you think something maybe stuck in the shell, (part of Violet or another previous critter) this maybe a route to try. But I would be very hesitant about any chemicals within the hermies shell. (one never knows if the shell will absorb them or not)

From: http://www.seashells.org/cleaning/liveseashells.htm

How to clean live seashells
It might be a good idea to check with local authorities where you will be gathering the sea shells as some areas prohibit the practice of collecting live specimens. If you are lucky enough to gather some live sea shells there are a few methods of cleaning that can be followed. Before starting to clean your live seashells you might also want to read through cleaning dead seashells.

1- Burying-This one is by far the easiest to do. Find an area in your yard where you don’t mind digging a hole and bury the seashells about 18 “( enough so animals will not dig them up). Let them remain buried until insects, larvae, worms, and bacteria remove all the tissue (a least a couple months). The longer the better. Go to step 5

2- Freezing- If number 1 is not an option then this method will work also. Place the seashells in a water tight bag and cover with water then place them in the freezer(just like you would fresh fish). When ready to clean allow the seashells to thaw at room temperature. After they are completely defrosted you should be able to grab hold of the animal inside and gently pull it out. Go to step 5

3- Boiling-Take a pot of water large enough to hold the seashells you are cleaning. Bring the water to a boil and let boil a few minutes(longer for larger or a great number of seashells). Using tongs and being careful not to burn yourself remove 1 shell and grasp with gloves or towel, so you don’t burn yourself, and gently pull out the animal tissue inside. Go to step 5

4-Microwave- This is an easy method if you don’t mind the smell in your microwave (my wife is not to fond of this method). The time you cook your seashells can really vary by microwave so really just try it until you figure out how long to put them in for and then treat them just like you would in step 3. Go to step 5

5-Bleaching-After no tissue remains soak the seashells in a 50-50 solution of bleach and water. There is no set time to let them soak because it various by the type of seashells and quantity of seashells being cleaned. Just make sure to remove them after the periostracum is gone. The periostracum is the flaky leathery covering that covers most live seashells.

6- Fresh water-Remove from bleach and rinse thoroughly with fresh water. If preferred you can rub the seashells with baby oil to give them a luster.

Notes of interest

1- If tissue should break off inside the seashells you are cleaning there are two ways to proceed. Shake the seashell vigorously trying to remove the extra tissue or sit it outside where flies, bugs and ants will crawl inside the seashells and remove any remaining tissue.

2-Operculums- This is the trap door of the shell that helps protect it from intruders. Many serious collectors like to keep this part of the shell to show that it was a live taken seashell


3- Water picks- Sometimes on smaller seashells another method to remove the tissue is to squirt them with a water pick and the high pressure will push the tissue out. This will only work with smaller seashells.

4- Dental picks- A lot of times dental picks and other instruments are used to help in removing barnacles and other growth on seashells. These can be purchased at many seashell stores. Try checking www.seashells.com .


does the smell really need to be gotten rid of though? I mean, for us, yeah, of course it’s WAY more pleasant to have a clean, non smelling shell for our crab to inhabit, but for the crabs, they probably don’t care. I guess that there’s a smell there for a reason – i wonder if there is some little decomposing bits of the previous crab still left. If thats the case, they probably do need to be cleaned. I know i’ve cleaned (just boiled) some shells, other’s I’ve just placed back in the crabitat – the crabs don’t seem to care too much.

Normally if there is a stench to the shell that cannot boil away when sterilizing it there is ‘something’ down within it. So it is best to try to get the odor to go away. As you said though, it probably doesn’t bother the hermies as far as the smell goes…but if there is something down within the shell it could harm their soft abdomen. I have had this happen a couple of times with new shells I have bought online. They appeared fine, no odor, but when I boiled them prior to offering them to the hermies oh my goodness the stink! :sick: After a few boils, an ocean water soak and another boil, not sure what it was but upon shaking the shell small bits of black substance came out of them. On one shell I had to do the ocean water soak a couple times and boil again after each soak before the stink went away and each time something black came out of the shell. :sick:
P.S. Sorry to say to, but this ‘might’ of been one of Violets complications too?

i guess that’s probably a pretty good rule to follow – if it smells, there’s something causing the smell and it’s best to get it out

Perhaps I’m just stupid and didn’t know this, but, I had a shell that needed cleaning. It had some funky green spots inside that I’m thinking had something to do with when my hermit crab, Daes, who was occupying the shell died. I didn’t want to use bleach on the shell to get those spots out and I wasn’t sure boiling water would be helpful. I guess I should’ve tried vinegar first, but nope. I decided I’d try lemon juice. I left it sitting overnight and this morning I dumped out the juice. The shell it self was crusty (strange) and that could’ve been scrubbed off. BUT …the lemon juice ate a hole through the shell.
So, the conclusion? Do not soak your shells in lemon juice to clean them. At least overnight.
And the worse part? It didn’t even get rid of the green spots!
So I thought I’d just post this and save everyone a shell.

FAQ How can I buff shells?

Rachelrmf asked:

I have alot of natural shells that i just love, but have recently (i know i am a bit of a blonde;;lol) relized that my shells are the same as all of the pretty ones i like they just are’nt buffed out. does anyone know of a fast and easy way to buff, polish them? I had ordered a black pica from Vicki and have relized that i have severel of the same kind of course the one i got from her was so much prettier so i got my nail files out and decided to file away on one and sure enough after 4 hourse and three blisters in now looks the same! I would really like to do this with all of my shells.

I have a bunch of pica shells I got from a pet store that had bleached them, so the crusty stuff clinging to them are all white. When I got these, I was wondering the same thing….how to get that stuff off. Hunter actually changed into one of them, but even though his abdomen is large the shell seems to be too heavy for him to lift properly and comfortably. The front of the shell rests right behind his eye stalks (peepers, I call them) when he walks. Now, he’s back in his old shell. Maybe if I buff the shell a bit it will lose alittle weight Confused So, Rachel, you used a nail file

lol i did! it really did do what i was wanting but wow that was some work involved. humm. maybe one of those rock tumbler things would work?

I’m in the process of using my dremel tool to take off some of the outer layer of some goldmouth turbo’s I have so they are more lightweight. Its a process! I’ve been using really coarse sanding wheels and after about four hours worth I’m kinda sick of it lol. There are lots of different bits for dremels so I’m sure it could be done with one of those minus the blisters lol.

ha ha where do i get something like that?

I wonder if one of those foot pedicure devices would work. The hand held thing with the spinning, gritty knob.
Or….wonder how much a jeweler would charge? LOL, yeah right!!
But seriously, I wonder if the above would work?

My hubby got me the dremel for $20 at walmart. Its a little cordless model and I absolutely love it lol. There was also a wide selection of bits there with the dremels but since he has TONS of bits I just use his lol.

LOL Not to go too off topic, but does any one have an idiot proof guide to using the Dremel? I have a new one that I’ve never used because I couldnt figure out how to get all the different tips onto it. I have wanted to hollow out/lighten some of my shells for some experiments, and I cant figure out how!

Ahhh you guys the dremel is an awesome tool! So many uses!!! jsrtist..your dremel came with a little wrench looking thing..use it to loosen the silver part where your bits go into, swap bits and tighten back up. (PS there should be a little button on the grip that you have to push in while you do this) Read the manual it should show you. Once you get the hang of it you will come up with endless things to use it on.
I wonder if one of the stone grinding bits would be better than a sanding one for shells?

Lol I absolutely love mine! Hubby has one of his own and I always wanted to use it so he surprized me with a smaller one of my own. His is pretty neat because of all the different attachments you can use, and its variable speed but I do just fine with my cordless little one that has hi and low speeds.
I’m planning on going to the hobby store when I get paid to check out some of the heavy duty craft bits they have there. So excited

FAQ Where can I get quality shells for my hermit crabs?

Where can I buy sea shells for my hermit crabs? Photo credtit - Marnel Rodriguez

Where can I buy sea shells for my hermit crabs? Photo credtit – Marnel Rodriguez

Sea Shell City:


Wonders of the Sea:

The Hermit Crab Patch:

Sea Shell World

Shell Horizons

Sea Shell Shop

Richard’s Sea Shells (Formerly Deltona Shells)

Searching on Etsy or Ebay will also yield a lot of results for shells.

If you know of another quality web site, please feel free to e-mail us the link so we may add it to our list.