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Discussion Starter #1
So I'm new at this

But how do you keep a hermit crab's tank humidity up?

I have a heating pad i got from petsmart on the outside of the tank.sadly I couldn't put it under the tank cause of the counter top I have could get harmed by the pad and I have hygrometer that reads 20-30,and I mist the tank everyday yet it seems the tank will not hold the humidity nor will it stay warm enough for the crabs even though I covered the lid to try to trap the humidity.Its getting the point I wanna put a second heater inside the tank.

I have a heating lamp but I'm afraid to leave it on when I'm not home and it getting knocked off by the cats

they are both in a 10 gallon tank

I feed them pellets

I have non painted shells but they refuse to leave their painted shells even though they're to big for them and is frustrating they won't change to bigger shells i have

I alter their water from salt to fresh

My crabs have stayed buried under the sand for 2 months now maybe almost 3 and I read I must assume molting and should not unbury them but how do I know they haven't died from suffocation or lack of heat/humidity in the tank?
hey haven't come up for food and water so i'm a bit concerned.

1,764 Posts
Oh hermies. Be able to help you there, since i have a gang of my own and a member of a few crab orientated boards!

First thing first, UTH make great additions in heating smaller tanks - termed crabitats by many - since they not like heat lamps which tend to dry out the tanks. In a hermit crabs setup, its better to place a UTH above the substrate line, on a side wall of the tank. This is due to crabs needing a deep substrate - ill get into that soon ;) - which the substrate effectively from a insulative block which does nit heat the air... but cooks the sand! Many in the USA and canada seem to go with a brand called Ultratherm, which runs hotter in comparison to those crappy store brought zoomed and the like. Your trying to achieve a temperature of at least 80F, pr at least over 75F min since these are tropical animals.

Substrate needs to be deep, many recommend at least a minimum of 6 inches or 3x - 5x the height of your largest crab. They use the substrate to bury for fun, but also to moult - which are very vulnerable at this time, and secrete hormones which other crabs are very 'in tune' with and van attack your moulter. Many seem to use playsand and/or EE (coconut fiber), which the most popular option is a 5:1 ratio of sand:EE. Playsand has the advantage of being cheap, while EE is good for humidity boost and water retention. Whatever you decide to choose, you want it to be sandcastle consistently so they cab bury and moult with ease.

For food, its best not to use store brought foods since it contains a lot of fillers, preservatives and pesticides that can make your crabs sick - they closely related to 'insects', so the common view is whats not safe for bugs... not safe for crabs. Many feed their crabs a 'raw' like diet, consisting of scraps of your fruit, nuts, meat, veg as their diet... which many also purchase organic produce to feed their pets - to reduce the chance of crabs getting ill of pesticides and the like. The each in small quantities, so one organic apple can last quiet a long time - up to and over a month - depending in frequency offered abd portion size. Things like honey are also good to offer, since it full of minerals and protein. Commin foods mosy liked by crabs seem to be fruits (apples, grapes, mango), meats and eggs.

Hermies require a cuttlefish bone, which is used for calcium uptake and shouls be provided one at all times. This can ve found at your local beach - be aware of local laws! - or for birds at your local pet store. They love munching on it!

Water for hermit crabs should be both freshwater and saltwater at all times, and should be deep enough so they can submerge themselves in - as long as they have easy ways to get in/out, they fine. They use this water to drink, but also to keep their abdomen hydrated by keeping a small bit in their shell - which they mix the two types to make their own required ratio... usually its brackish. Stay away from salts listed for hermit crabs, they are complete junk and a waste of money - in fact, most things labeled for crabs are either dangerous or a waste of money! Basically, hermit crab salt is table salt in fancy packaging, and cost twice as much. Instead, you want salt to be for marine organisms - like reef tanks - which closely mimics nature and supplies the crabs with important minerals thats difficult to include in their diets - and keeps them happy/healthy. Im the Americas, instant ocean seems to be a popular brand. Many use small tupperware containers as a water source, with rocks/plastic plants and/or plastic needlepoint canvas as a ramp to get in/out.

Shells. Its important to offer natural shells - glad you do! Depending on the species of crab you have, they seem to have particular taste in the type of shells. Good shell choices include turbos, which many species seem to like. This can be found at your local arts and crafts - in a small bag - or online... petsyore shells seem to be overpriced or the wrong type so many crabbers stay away from those.

As for humdity troubles, what is your tank sitting at? (Ideal is 80%). Adding moist substrate - like EE at sandcastle consistency - as well as airstones in the water pools, a glass lid and a nice moss pit - using sphagnum moss - will help keep your tank humid. Have you also calibrated your humdity gauge - analogs in particular can be way off! Calibrations involves a plastic zip lock bag and some salt - your cooking salt... i mean 'crab salt' will work fine for this - and wetting the salt until its a white mushy mess - but not dissolved, think of it like snow... after a couple of hours - recommend leaving it for a day - it should read around 75%... if not, your gauge is reading higher/lower. EG if its reading at 65%, you know its around 10% off... so in your tank, a 68% reading is actually 78% - which is fine. Just whatever you do, stay away from sponges - they just a bacteria factory and require daily microwaving... which requires it to be completely dry otherwise it will shrivel up into the size of a walnut!

Any questions - sorry for the read! - feel free to ask, be happy to help!

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