Basic Hermit Crab Care
At A Glance
An example of a hermit crab tank:
Lifespan: Up to 40 years is possible in captivity though 10 to 20 years is more common. In the wild,
50 to 70 years has been reported.
Size: Young crabs (under 2 years) are 0.5 inches across and can fit on a dime. Full grown adults (25+
years) reach 6 inches and are larger than a softball. Average size (5 to 15 years) is 2 to 3 inches.
Housing: Minimum 10 gallon aquarium for small crabs, with larger tanks required as they grow.
Minimum 75 gallon aquarium when fully grown. Wire cages and open topped enclosures do not hold in
heat or humidity and should not be used in non-tropical areas.
Climate: 80 to 85 degrees and humidity levels of at least 75%. Purple Pinchers can handle slightly
lower temperatures down to 75 degrees.
Substrate: Children's Playsand (silica based) or cocofiber, or a mix of the two, and many crabbers
prefer a 5:1 mixture of sand to cocofiber. Must be kept moistened, enough so the substrate keeps its
shape when squeezed but not so much it drips. Substrate should be at least three times deeper than
the crab is big, which usually means filling the aquarium halfway.
Water: Dechlorinated water must be used, and using a product that binds heavy metals is
recommended. Water bowls should be deep enough for the crab to submerge with a way for them to
safely climb back out. Both fresh and salt is required. Saltwater should only be mixed using a product
for marine fish.
Diet: Hermit crabs are omnivores and scavengers. Fruit and protein (meat, insects, seafood) should be
provided daily. Vegetables and plant matter such as oak or maple leaves are welcome additions.
Hermits are affected by pesticides and fertilizers, so care should be taken when sourcing food.
Molting: Crabs molt to grow, which can take weeks or months. They will bury under the surface and
not return topside until they are finished. This is why there is a need for such deep substrate! Never
disturb a molting crab as digging it up may kill it.
Shells: 3 to 5 shells per crab, and they must be a proper species of shell and slightly larger than what
the crab is currently wearing. Please do not offer painted or glazed shells - they are dangerous and
potentially toxic to hermits. Natural and polished shells can be found online and in craft stores.
Breeding: Hermits do breed in captivity, but live young are not possible without special equipment
and a lot of effort.
Maintenance: Food should be changed daily to prevent mold growth. Water bowls should be
changed when dirty or at least every third day. Spot clean as needed to remove waste and uneaten
food. Glass can be cleaned with white vinegar as needed. Monitor substrate for signs of dryness and
spray with freshwater as needed. Substrate almost never needs to be changed unless it becomes over
saturated. If the tank is not over saturated and you feel strongly about changing it, please wait until all
molting crabs are finished and on the surface for safety!
Shopping List (Basics)
❑ Hermit Crabs - they need friends
❑ A Place for Them to Live – aquarium, 10
gallon minimum, based on size and number of
crabs
❑ A Lid - screen lid w/clips or aquarium lid
❑ Heat Source - under tank heater for use on
back of tank, or heat lamp
❑ Water Dechlorinator – for fish or reptile
❑ Substrate - silica playsand and/or cocofiber
❑ 2 Water Bowls for salt and fresh - they need
to be deep enough to submerge in
❑ Salt Mix – made for saltwater fish only
❑ Thermometer and Hygrometer
❑ Extra Shells – natural, the same size and
larger than what the crab is currently wearing
❑ Food - natural fruits, insects, meat and
seafood
❑ Food Bowl - or clam shells
❑ Items to Climb On – decorations or
driftwood
❑ Places to Hide - cocohuts, caves, fake plants
❑ Plants for Cover - silk or plastic
❑ Hand Mister - or electric fogger
❑ Reptile Moss (Optional)
❑ Calcium Source - cuttlebone, crushed coral,
egg shell
I Bought a Crab, Now What?!
There are many myths and inaccurate care sheets and advice out there, so please read on! Hermit crabs
come from tropical regions; therefore, they have a few easy, yet essential requirements for their “home
away from home” - which we call a crabitat. Once these basic requirements are met, you will find
hermit crabs to be a relatively simple yet rewarding pet to care for. This care sheet and other articles on
our site will help you to understand what those needs are, and will help you to set up a home for your
new hermit crab. Hermit crabs can live for decades with proper care, so giving them the perfect home is
important.
New Hermit Crabs
While the name implies they like to be alone, that is far from the case! In the wild, hermit crabs travel in
colonies that number in the hundreds. Most hermit crabs benefit greatly from having friends—in fact,
it’s very important for them to have the company of their own kind. You’ll also be able to watch them
interact, and their behavior in the presence of other crabs is closer to what it would normally be in
nature. Size does not matter to a hermit crab, so feel free to mix tiny crabs with jumbos. Crab
companions should only be other hermit crabs though; do not place them in the same enclosure as
other reptiles, amphibians, or mammals. A healthy crab can be seen walking and waving its antennae
happily, either on its own or when you pick it up (hold your hand flat so it can’t pinch!). Crabs in natural
shells are usually healthier than crabs that were forced into painted or decorated shells. Most crabs
dump their painted shell first chance they get.
New crabs can be kept in a separate ISO tank for a few weeks to a month – both to help them graduate
to the improved conditions, and to prevent introducing crab mites to your current hermit crabs. Many
crabbers choose to add new crabs immediately to their main tank. New crabs should be bathed at least
once before upon coming home to make sure they do not have mites. When introducing new crabs to
the main tank, give them a dip in tank temperature declorinated fresh water which will make them smell
familiar to the other crabs. It can help to prevent any bullying or fights with your existing crabs, and
make the introductions go much smoother.
All hermit crabs are wild caught, and not all make the transition from life in the wild to life in captivity.
They also take a very long journey from the tropics in less than good conditions to reach the stores
where they are sold. Some hermit crabs will start to slow down and may unexpectedly die after being
bought. This is known as Post Purchase Syndrome. Any crab that is new is at risk of sudden death until
it has completed its first successful molt in captivity.
What Kind Is It?
All land hermit crab species except the giant coconut crab begin with the name Coenobita (C.). They are
born in the ocean, but quickly transition to life on land and live on ocean beaches as well as further
inland in tropical rainforests near the coast. Do not confuse them with marine hermit crabs, which
spend their whole lives in the ocean and only emerge at low tide to forage. The most common species
of land crab in captivity are the Purple Pincher (C. Clypeatus), which has a big purple pincher with light-
orange to dark-red legs, and the Ecuadorian (C. Compressus) which has smaller claws, gray-green to tan
coloring, and big eyes that look like “()”. Ruggies (C. Rugosus), Indos (C. Brevimanus), Violas (C.
Violascens) , and Strawberries (C. Perlatus) may be found at some pet stores, but they are a rarity to
find for sale. Different species can be mixed together, but you should have at least two of each species
so that they have a "species buddy".
The “Crabitat”
Most new owners purchase a hermit crab in a small plastic container usually referred to as a critter
keeper. While these cages are good for an isolation tank and temporary lodging, they aren’t large
enough for everyday living. By the time the dishes for food and water, the deep substrate they need,
and fun decorations are added, there’s no room left for the crab! Aquariums are a way to give your crab
more space to live, and also give you more room to decorate. These can be purchased new, but since
the aquarium doesn’t have to be watertight you can buy a used tank at a reasonable price instead.
Another option is to use large plastic storage containers or very large acrylic animal cages—these are an
extremely inexpensive way to give your hermit crabs a large living area.
Remember that the more crabs you have, the more space they need, especially when they start
growing! Every crab needs enough room to molt safely and to have their own space to get away from
the other crabs if they feel the need. For a medium crab, the minimum necessary size is a 10 gallon
glass aquarium. For long-term housing, each crab needs at least 5 gallons of space and even more than
that as they grow bigger. Hermit crabs move around and exercise a lot more than you may think since
they are most active at night, and they will stay healthier with a larger enclosure. For a baseball-sized
crab, a 75 gallon or larger tank is the best possible home. Please keep in mind that hermit crabs can be
overcrowded, and that every crab needs to be able to have its own space to molt safely. Some hermits
can grow very quickly, so that tiny crab in a 10 gallon tank could be a very large crab needing a larger
tank in a year or two!
Hermit crabs are expert climbers and are stronger than they look, so a lid should always be used. Lids
will also hold in the heat and humidity that hermit crabs require. Aquarium hoods and glass lids are best
when used in conjunction with heating mats, although any openings should be covered and secured
with duct or packing tape. Reptile screen lids are perfect for use with heat lamps, though you may need
to cover the areas around the lamp with plastic wrap or aluminum foil to maintain a high humidity level.
Lid clips are available for use with screen lids; these clips prevent escapes while still allowing for easy
access. Plexi-glass can be used instead of glass, but please keep in mind that it is plastic and can melt or
give off toxic fumes if it is allowed to get too hot.
Tropical Conditions
Humidity Gauge (Hygrometer)
Hermit crabs breathe using modified gills: not quite fish gills; not quite human lungs. Their gills must
remain moist at all times or they will slowly suffocate. It is therefore essential that their crabitat have
sufficient humidity. A humidity gauge, which can be purchased with reptile supplies or in the home and
garden section of most stores, is one of the most important crab supplies. Ideal humidity is between
70% and 85%, and by contrast most houses are only at 40-50%. Do not allow your crabs to be exposed
to humidity levels below 65% for extended periods of time. Levels above 80% are safe for hermits but
may encourage mold growth. Never guess on what the humidity is in your crabitat! Making sure the
humidity level is ideal is important to your crab’s wellbeing.
Sources of Humidity
Getting the humidity above 70% can be tricky at first. Keeping the humidity high may also be a
challenge if you run an A/C in the summer, and when the furnace is on in the winter. Misting with
freshwater is the most common way of raising the humidity level, but if it is the only method used it may
need to be done a few times per day. The tank and lid should be mostly sealed to keep the humid air
from escaping, but make sure to leave some vents for fresh air to enter the tank as hermit crabs do
breathe oxygen and low levels may cause health problems. Using large water bowls often helps with
humidity, as the heat lamps or UTH will evaporate the water to increase humidity. Using moist reptile
moss will also help with keeping the humidity stable, and the crabs will enjoy having a 'moss pit' to hang
out in. However, the key to keeping humidity up is a moist substrate, so watch closely and make sure it
isn't drying out. Using more cocofiber will also increase the amount of humidity in the tank. For serious
crabbers with humidity problems, try a reptile fogger or humidifier - many models come with timers and
are very easy to set-up and use to keep your humidity stable!
Temperature Gauge (Thermometer)
Since they are from the tropics, Purple Pincher hermit crabs need to be kept between 75 and 85
degrees. Exotic species such as Ecuadorians need higher temperatures of 80 to 85 degrees. If your
home is not this warm during the summer or winter, there are options to help! Products made for
tropical reptiles are perfect for helping to replicate a hermit crab’s native environment. If the
temperature falls below 70 degrees for too long, they begin to go dormant, and may not survive. A
thermometer should always be used to monitor temperatures in case of a heating failure.
Under-Tank Heater (UTH)
These are the most popular option for warming crabitats. They are sold for reptiles for use underneath
the tank, but in hermit crab enclosures the UTH should only be used on the side or back of the tank.
Because of the need of thick substrate in crabitats, UTHs are not effective when used on the bottom and
can possibly overheat and become a fire risk. Do not pay attention to the recommended tank size on
the packaging - buy the largest sized heat mat that you can fit on the back of your tank as many store-
bought UTH run too cool to heat a crabitat. Ultratherm brand UTH must be ordered online, but they are
known to run the warmest and are capable of being insulated with Styrofoam to boost the heat unlike
many other brands. If the UTH runs too warm a plug-in lamp dimmer or thermostat can be used to
adjust the temperature. Many crabbers prefer to use a pad that ends above the substrate line so that
they do not have to worry about substrate drying out quickly. Also, UTH cannot be bent without
damaging them.
Heat Lamps
Heat lamps are an option that will provide a lot of heat, which is great if your house is kept on the cooler
side. There are many types of heat lamps to choose from, and the larger the dome the more heat will
be reflected into the enclosure. It can be difficult to find the right wattage of bulb to get the enclosure
to the right temperature, so a rheostat (plug-in lamp dimmer) or dimmable clamp lamp can be very
beneficial when using heat bulbs, as this will allow you to cool down and adjust a lamp that is running
too hot. Small 10 gallon tanks may need to start out with a 25w bulb while large tanks may need more
than 100w. Hermit crabs are nocturnal and need to have darkness at night, so special reptile bulbs
(moonglow, infrared or ceramic) are the best as they can be kept on all night long. However, do not use
blacklights or party lights, as these emit lots of UVA and are quite different from reptile bulbs.
Other Sources of Heat
Heat rocks can burn your hermits, and heat cables can be pinched through causing an electrical hazard.
Daylight heating bulbs can be used during daylight hours only, but watch to make sure that the crabitat
doesn’t cool off too low at night. Florescent and UVB bulbs will give you viewing light during the day but
will have very little effect on the temperature. If the room they are in stays warm enough, you may not
need to add any supplemental heat.
Substrate
Hermit crabs grow by molting: during this time they tunnel underground and shed their hard
exoskeleton, revealing a very soft new skin that hardens over a period of days. They also bury to
destress, or for fun, or if conditions in the crabitat aren't good.
For substrate, a mix of regular silica-based children's playsand from the hardware store with either loose
or compressed cocofiber from the pet store works the best. Playsand comes sterilized, washed, and
screened, so it is ready for use right from the bag and it costs just a few dollars for enough to fill the
entire tank. Cocofiber holds and releases a lot of moisture, so it is a wonderful way to increase the
humidity of a tank. Most crabbers will recommend a mix of 5 parts sand to 1 part cocofiber, and you
can also add in small amounts of crushed coral or organic worm castings. Fluker’s Farms has recently
come out with a hermit crab sand that is made of cocofiber and silica sand—this is the only hermit crab
branded sand that is safe.
Substrate must always be kept moist. When wetting substrate, make sure that the water has been
treated with dechlorinator to make it safe. Sand should be moistened to the point where it just holds its
shape and you could build sand-castles with it. Cocofiber should be kept on the dryer side where it is
damp enough to hold its shape but no water drips out when it’s squeezed.
For substrate that stays fresh for a long time and resists mold growth, you can use regular strength salt
water when wetting it down the first time. The salt helps the humidity levels stay high, and it will also
help to prevent mold from growing. Always use freshwater to rewet the sand, as the salt will stay in the
substrate and adding in more can make it become too salty over time.
Hard and chunky substrates like gravel and mulch should never be used with hermit crabs since these
substances are hard to dig into and will not hold tunnels or caves. Calcium sands should not be user
either as it smells bad when wet, is porous which allows bad bacterial growth, is sticky which can
encrust their legs and abdomens, and when it starts to dry out it can harden into a cement like block.
Shells
Hermit crabs have a soft, delicate abdomen and in order to keep it protected they wear shells on their
backs. These shells are not a physical part of the crab, rather they are borrowed from other shellfish. As
the crab grows, it will need to move into bigger and bigger shells. Some crabs just love to change shells
for fun, or to find a better fit. Always have a broad selection of different sizes as some hermit crabs like
to wear shells that seem too large or too small for them. The more hermit crabs you have, the more
shells you should have available. If a crab does not have enough shell choices, he may try to force
another crab out of its shell and steal it. Neither you (nor another crab!) should ever try to force a crab
out of its shell. New shells should be sterilized in boiling dechlorinated water for five minutes and
allowed to cool before being given to your crabs. Individual crabs and some species like Ecuadorians will
often be stubborn about changing, so as long as you have provided proper sizes and proper shell
species, it is okay if your crab does not change shells - it just means he's happy with what he has!
You should provide at least three to five shells of each size needed by your crabs. The perfect sized shell
has a circular or oval shaped opening the size of the crab’s big pincher; however, some crabs enjoy shells
that are either too big or too small for them. Crabs cannot fit their bodies into shells that have thin
openings. Each species has its own likes when it comes to shell species, so it's a good idea to research
what they may enjoy the most before shopping for new shells. While painted shells are very pretty, the
paint itself is toxic to the crabs and they should be avoided. Natural shells are very beautiful, and there
are many different types of shells that hermits enjoy wearing. There are online shops that sell natural
shells, and some craft stores carry them as well.
Water
All water going into the hermit crab tank needs to be dechlorinated—for drinking, misting, cleaning, or
wetting substrate. Any fish or reptile dechlorinator that removes chlorine, chloramine, and heavy
metals will be perfect. Letting water sit for 24 hours or using plain dechlorinators will only remove
chlorine, and does not remove the more harmful chloramines and heavy metal ions. Bottled natural
spring water is also okay as long as you are sure it is completely natural as many bottled waters are just
tap water with a fancy name on the label. There is some concern that distilled or reverse osmosis (RO)
water may not have all the minerals crabs need, but supplying properly mixed salt water this shouldn’t
be a problem.
Hermit crabs require two types of water—fresh water and ocean water. Providing them with both salt
and fresh water allows them to regulate their salinity themselves, which is essential for maintaining
their shell water and health. Their dishes should be deep enough for them to completely submerge so
they can self-bathe whenever they feel the need. Hermit crabs will go swimming if given the chance,
but whatever container you use must have a way for the crabs to climb back out as they will drown if
trapped underwater for too long.
Hermit crabs live on beaches, and thus require a source of salt-water. Do not use table salt however – it
contains only sodium chloride and also has chemicals to keep it from clumping that may harmful.
Always use a marine salt mix, which is sold with salt-water fish supplies. Marine salt contains nearly 70
different elements and minerals and will perfectly mimic sea water. The most commonly found brand is
Instant Ocean, and this is available in small boxes and larger bags. Please note that while salt sold for
freshwater aquariums and (ironically) specifically for hermit crabs are not dangerous, they do not
contain the extra elements needed and should not be used. You will need to dechlorinate the water
used with the salt mix.
Hermit crabs do not need to be bathed. Crabs carry water in their shells at all times, and each crab likes
to have its own personal mix of salt and fresh water. Bathing them ruins this mixture and can also stress
them. The activity that occurs during and after a bath is a sign that they are frightened and are
panicking.
Diet and Supplements
In the wild, crabs are scavengers and will eat just about everything they come by, from plants to dead
animals - but this doesn’t mean you can just feed junk to your hermit crabs! Not many commercial foods
are recommended as they contain preservatives such as ethoxyquin and/or copper sulfate which pose
long-term health risks, or contain unnecessary chemicals. As a staple diet, you should feed your crabs a
variety of fresh or dried fruits and vegetables, whole grain foods, egg, meat, fish, poultry, other seafood,
and also dried insects. Calcium powder, crushed coral and shells, crushed cuttlebone or eggshells
should be provided at all times to help their exoskeleton stay strong.
Crabitat Items
Climbing
Crabs love to climb, exercise, and practice acrobatics - some species are known as 'tree crabs' as they
are found climbing trees in the wild. Providing climbing items is essential for their comfort. Cholla
wood, cork bark, mopani, drfitwood and large coral can be found in pet stores and these items are easy
to climb and they make a good snack! Safe woods can be collected for free from your yard as well if they
have not been exposed to pesticides and fertilizers. Explore ways of creating second levels for your
crabs, as this will give them high areas to hang out in, and also increase the square footage of your tank.
Hides
Each crab needs their own little “spot” – a safe place to retreat to for resting and to relieve stress. You’ll
need to provide some type of shelter, such as a hollow half-log, plastic cave, or coco-hut. Crabs will also
hide behind fake plants. You should have enough hiding spaces for each crab, otherwise your crabitat
may be too crowded and this will stress the crabs. The more plants and shelters they have to hide in,
the safer they will feel and the more you will see them. Insufficient shelter can cause hermits to bury
underground more often.
Decorations
Anything sold for reptiles and fish is generally recognized as also being crab safe. You can also find
natural wood and fake plants at craft stores and dollar stores. Watch to make sure that whatever you
are using is non-toxic and isn’t make of a material where the crabs can pinch off paint or parts of it.
Crabs will pinch and destroy anything they can get their claws on!
Items to Avoid
Crabs should not have contact with anything chrome, as chromium ions are dangerous. Nickel, arsenic,
and cadmium are also dangerous. Don’t use Spanish or decorative moss, as this is actually colored pine
shavings, or craft moss as it may have pesticides. Also, be aware that iron will rust in the high humidity.
Molting / Disappearing Underground
Hermit crabs grow and heal by molting, and during this time it is very important not to dig up or disturb
your crab. When a crab is molting they spend that entire time underground without surfacing—not
even to eat or drink. Unfortunately it’s a very boring time for us owners! A deep, moist, diggable
substrate is essential to a successful molt. Your crab will likely completely bury for several weeks or
months as they need the dark seclusion of the underground for their molting hormone (Ecdysone) to
work. The water pressure maintained with the moist substrate allows them to bust out of their
exoskeleton. If crabs are prevented from burying in moist substrate, or are regularly dug up, they can
build up a molt-inhibiting hormone (Xanthurenic acid) which can have dire effects.
The time it takes for a crab to molt is determined by the size of crab and also by the crab itself, so there
is no way of knowing just how long it will take. Smaller crabs generally molt faster and more often than
larger ones. The time spent underground can be anywhere from 3 weeks to 3 months, sometimes
longer. Small crabs can molt once a month, while jumbo crabs may wait 12 to 18 months between
molts.
During this period they will find a safe and quiet place under the substrate to build themselves a little
cave. They will then shed their exoskeleton (skin), which will look exactly like the front-half of a crab,
but will be empty inside. Once the exoskeleton is off and they’ve have a few hours to a few days to
harden up the new skin, they’ll start eating their old exoskeleton to reabsorb the lost minerals and to
help strengthen their new exoskeleton. They’ll then rest underground until they are completely
hardened up and are ready to return to the surface.
Some warning signs that a molt may happen soon include the crab having an ashy or grayish
appearance, blurry or cloudy eyes, confused antennae, the growth of a molting sac (looks like a black
jelly bean just behind their back left leg), digging more often than usual, eating more than usual, and
spending a lot of time around the water dish. Some crabs give off no signs at all. If a crab is missing a
limb, you might see a small ball of clear gel begin to grow, this is called a gel limb, and is a sign that it will
regenerate with the next molt.
Sometimes a crab will shed it’s exoskeleton without burying underground. This is called a surface molt.
These are very dangerous for a crab and are usually a sign that something is wrong with their enclosure.
If this ever happens, stay calm! Do not touch the crab as this can injure them. Cover the crab with a
hide or other object that will block out light, and make sure any other crabs you have cannot get to the
molter. The molting crab should be able to finish eating his exoskeleton and can join the other crabs
once he’s moving around and eating normal food again. You can also isolate him in the tank with the
top-half of a plastic bottle (with the cap open for air) to prevent other crabs from bothering him. If you
pick up a surface molter, the exo may look like a dead crab falling out. Check way back in the shell for a
newly molted crab before starting the funeral! He will need to eat the old exoskeleton in order to regain
the lost calcium and nutrients, so don’t take it away.
Hermit crabs can regrow entire body parts when they molt. Limbs, pinchers, antennas and even eyes
can reform in one molt or over a span of several molts. Hermit crabs who have been attacked and lost
all their limbs have successfully survived by being cared for until they were able to molt again. Newly
grown legs are often skinny and brightly colored, and new pinchers will be undersized, but usually within
two molts they will be back to looking normal. Injuries can also be repaired while molting.
Breeding
Hermit crabs can breed in captivity, and it's a sign of a healthy cabitat and happy hermit crabs. There is
a good dose of luck involved as you must have two mature individuals of the opposite gender, which not
all crabitats will have. Mature females are around medium in size, and the largest of males will win the
fights for the right to mate with them. In the wild they have very set molting schedules of once per year,
but in North America, captive crabs seem to breed between February and August with the most reports
occurring in June and July. Eggs are ready to hatch roughly a month after mating occurs, and you may or
may not see signs of the zoea in the water dish or eggs spread around the enclosure as the mother and
other hermit crabs will eat them.
It is almost impossible to rear young hermit crabs. Their larvae are ocean plankton for weeks after
hatching, and it takes specialized equipment and a lot of time and effort to get any to survive in
captivity. Only a few people have ever managed this successfully, and several have tried. We hope that
more owners will try in the future as we learn more about the process. Someday we may be able to
breed hermit crabs readily in captivity, and hopefully there will be no more need for wild harvesting.
Maintenance
Assuming you provide your crabbies with a proper environment, they require relatively low
maintenance. You should check the temperature and humidity every day and make adjustments as
necessary. For instance, if the humidity is too high, you can prop open the glass cover a bit, or remove a
small amount of saran wrap from the mesh. If the humidity is too low, you can prop the cover less, add
more saran wrap, or check to make sure the substrate is staying moist enough. You should also remove
any fresh food from the previous day to prevent spoilage, and make sure the water dishes are full and
clean. Keeping the water clean is of utmost importance, as crabs can be very sensitive to water quality.
Every week, you need to completely clean out the water and food bowls.. If you have large water basins
that are filtered and aerated, they still need to be completely cleaned once a month unless they are
cycled. You can also spot-clean poo from the tank, although if your sand or coconut fiber is kept
properly moist, beneficial microbes will naturally recycle the poo.
In the past it was often recommended to completely change your substrate after a set period, but many
crabbers now choose to wait until the crabitat actually needs such a deep cleaning rather than follow a
set schedule. Many have been using the same substrate for years with no problems! If you feel the
need, substrate can be fully removed and replaced with fresh, and some old substrate can be retained
to mix into the new to retain a familiar scent and for the good things that might be in the substrate. Try
to work around the times when your crabs are molting so that there isn't any risk to them. It’s never a
bad idea every few months to wash items in the tank in hot water. Cholla, driftwood, and cork can be
microwaved for a couple of minutes while wet to kill any bacteria or mold.
Regular bathing used to be recommended, but it is no longer. Hermit crabs auto-regulate the salinity of
their shell water (osmoregulation), and stock up before molting. Bathing disrupts their shell water and
can stress them, plus you should never dig up buried crabs. Provided the proper fresh and salt water
bowls, they will clean themselves. The only time baths should be considered is when you are
introducing two unfamiliar hermit crabs, adding a new crab into an established tank, or when one crab is
getting picked on. Making the new or picked on crab smell neutral will often prevent or stop fights.
Common Crabitat Issues
If you use any organic climbing or hiding structures, like wood and wicker, don’t partially bury it in the
moist substrate, or it may start to mold underground. Some mold growth is pretty much unavoidable in
a crab tank, and while it's not good for us humans, it causes no health issues to the hermit crabs. Simply
remove the affected items and clean them by boiling, baking, microwaving, or soaking in salt water.
Allow wooden and natural items to dry completely before returning to help prevent mold from
returning.
Finding random insects and harmless mites in the crabitat is also extremely common. These things are
already living in our homes, but the heat and humidity of the crab tank attracts them. In many cases
cleaning the tank completely will do nothing to help as more are still present in the area and will come
back once the tank is set back up. Springtails, isopods and food mites actually act as a living clean-up
crew, breaking down waste and helping to prevent mold. Fruit flies can be dealt with using an easy an
non-toxic vinegar trap.
© 2004, 2006, 2015, 2017
Ashley Wise; JediMasterThrash@comcast.net | Rachel Hamilla; wode[email protected]
Permission granted to print, copy, and distribute this document as necessary to promote proper
hermit crab care.
