In the wild, Hermit Crabs live in hot environments within Australia. Sitting in the high 20's to low 30's. To keep them happy, healthy and thriving in captivity it is vitally important that we supply them with a tank that meets their heat needs. They depend on the right environment to regulate their body temperature.
26-32.c degrees is the perfect temperature for Australian Hermit Crabs in captivity. This range helps humidity to sit stable and keeps your hermit crabs active and warm.
Anything below 26.c is too low and can cause your crabs to go into an unnatural hibernation, and anything above 32.c can cook your crabs and cause them great distress.
You must remember that hermit crabs are a tropical species, so they can handle small temperature fluctuations for short periods of time.
It's too cold in here!
If you find your temperature dipping below 26.c, it is very important to try and raise it back up into the safe temperatures. Hermit Crabs can live in cold temperatures for a short amount of time, a few weeks, but any longer and they will start to struggle. If your temperature gets far too low, your crabs may go into an unnatural hibernation.
Hibernation is not something that hermit crabs will naturally do and is usually a last resort to sustain life. They are a cold-blooded species, which is why they need constant heat. Anything below 20.c degrees and they will be forced into hibernation, however they cannot regulate their metabolism or body temperature. This means if they do go into a forced hibernation, they may not be able to come back from it.
It's too hot in here!
Temperatures above 32.c can make your crabitat a bit too hot for your crabbies, if it gets too hot in there, they will usually dig down below the substrate to cool down. But this is not always the best option, if they are constantly below the substrate trying to cool down, they won't have access to food or water and can often become lethargic and can often be found hanging out of their shell to try and cool down. This is not a good sign and can lead to permanent damage and death.
Leaking of a brown liquid or foaming at the mouth are signs of severe overheating and is likely something the crab will not be able to come back from and will result in permanent damage or death.
Heating up your tank
The best way to heat up your tank is to use appropriate heat sources such as reptile heat mats and heat cords. Stay away from heat lamps, these do nothing but dry out the substrate, burn crabs and create hot spots within the tank.
Placement of your heat source is very important, heat sources should be placed above the substrate line, on the back or sides of the tank. Never place your heat source under the tank or below the substrste line! This will heat up the substrate, causing it to dry out and overheat your moulting crabs. Pet stores will tell you that you need to place your heat source under the tank, this is simply not true. You only want to heat the air in the tank, not the substrate.
Cooling down your tank
Tanks getting too hot is a common occurrence in summer, this is usually when you will find yourself needing to cool your tank down to the correct temperatures.
Start by removing extra heat sources from the side of the tank first, remove any extra insulation, this will also help in bringing the temperature down.
If some of your heat sources are not able to be removed, you can turn them off at the power source, or turn the adjustable dial down on your adjustable heat mats.
Try not to open the lid or put gaps in the lid, as this will suck out your humidity.
Close any blinds near the tank to prevent sunlight from heating up the tank, you can also run the air-conditioning or a fan to bring the room temperature down.
Tips & Tricks for tank heat
Thermostat - Having a thermostat for your tank can be a fantastic investment, although not cheap, they can be a great stress relief for yourself. Thermostats will turn the heat sources on when the temperature gets to the set minimum and turn them off when the temperature gets too hot. This helps to keep your tank within the correct range, without having to worry too much about altering the heat sources. Simply plug your thermostat into the wall, plug your heat sources into the thermostat and place the gauge inside the tank.
Blankets - If used correctly they are not a fire hazard. Never place a blanket directly over the heat source or electrical boards. Place your blanket on top of the tank or draped over the front of the tank, this is completely safe and is a common practice within the hermit crab community. By placing a blanket on the top or front of the tank, you can help raise the overall tank temperature.
Insulation - Insulating over your heat source will greatly increase your temperature. Upto 20% of the tank heat can be lost when you don't insulate. You can use insulation mats, car sun shields, foil or styrofoam. Simply place your insulation over the top of the heat source and tape it down.
Sealed tank - Having a sealed tank will keep your heat from escaping. This is why we never recommend having a mesh lid or sides on your tank. You can fill gaps with pieces of cloth, insulation, styrofoam, cling wrap, perspex or tape.
Heater/Air Conditioner - Be mindful if your tank is sitting close to a heater or air-conditioner. This can affect the overall heat in your tank, causing it to climb too high or drop too low.
Tank placement - Tank placement within your house is very important, does your tank sit to close to a window or door where cold air may come through? Does it sit directly in the summer sun? These things can alter the temperature. If close to a window, it may drop too low during winter and if sitting in direct sunlight, may climb too high in summer. If you want your crabs to have access to 12 hours of day and night, place an LED aquarium light above their tank.
Remove/Add heat sources - If you are struggling to bring the heat up in winter, you can try adding extra heat sources to the sides of the tank, or purchasing a higher wattage of heat mat/cable. We recommend a minimum of 20W atleast. Anything under will make no difference to the heat of your tank. When it comes to heat cords, it is not about the length, but about the wattage. If your tank is getting too hot in summer, remove any extra heat sources or turn them down to compensate for the summer heat.
Quick temporary fixes (hot water bottles & hot hands) - We don't mean an actual body hot water bottle, they can and will crack your tank glass. What we suggest is filling a water bottle with hot water (a heat proof drinking bottle such as stainless steel) wrapping it in a towel and placing it inside the tank. This can help radiate a small amount of heat and gives your crabs the option to snuggle up against it to keep warm if your tank is far to cold. You must cover the bottle with a cloth to prevent crabs from being burnt. You can also place "hot hands" on the outside of your tank, it's not going to give you a huge rise, but anything is better than nothing. These solutions are only temporary and should not be relied on as your main heat source.
How to place your heat sources
Heat Mats -
Heat mats should be placed on the back or sides of the tank, they must sit above the substrate line. To stick them down, you can use insulation tape. Insulation tape is heat proof and sticks the heat sources down really well. Usually found at Bunnings. Line up your mat so that the bottom of the mat sits just above the substrate line and use tape to tape all 4 sides of the mat to the tank, you don't need to tape the entire back of the mat, just the edges to keep it stuck down.
Heat Cords -
Heat cords should be zig zagged along the back or sides of the tank, leaving a 3-4cm gap between each line. Use insulation tape to stick down each part of the cord as you zig zag it down your tank until you reach the end. There will usually be a little notch on your cord to tell you where the heat source ends and the electric cable starts.
To ensure your cord is sitting against the tank, once finished zig zapping, cover the entire heat cord in insulation tape.
The steps for this are pictured below.
*Heat Cord zig zagged down the side of the tank, above the substrate line.
*Heat Cord completely covered in insulation tape.
*Insulation Mat taped down over the heat cord.