You should place the heat source at one end of the tank, rather than the middle. The end where the heat source is will be referred to as the 'warm end', while the opposite end will be referred to as the 'cool end'. This creates a temperature gradient so that your hermit crabs have the option of moving to the cool end if they feel hot and to the warm end if they feel cold. Remember to plug the heat source into your thermostat. The thermostat sensor should be placed in the hottest area of the tank.
How do I measure the temperature?
If you are using a UTH, then you only need to worry about the temperature of the bedding, so push the thermometer deep into the bedding. The bedding temperature may be much higher than the air temperature. For this reason, you should bury the thermostat sensor deep in the bedding near the UTH so that it does not bake the bedding. You should also check the bedding temperature at different areas of the tank. Otherwise, if you are using a ceramic heat emitter, then you only need to worry about the air temperature, so place the thermometer on the cool end of the tank, since the thermostat will monitor the temperature of the warm end.
What temperature should hermit crabs be kept in?
If you remember what temperature the pet store kept your newly adopted hermit crabs in, then you should begin by setting the thermostat to that temperature. If the pet store kept their hermit crabs in temperatures below 22°C (72°F), then set the thermostat to 22°C (72°F). Each day, increase the thermostat setting by 2°C (3°F or 4°F) until you reach 28°C (82°F). If the newly adopted hermit crabs came from a tank that was already at 28°C (82°F), then keep the warm end of your tank at 28°C (82°F) from the first day. Pay attention to the temperature of the cool end. If you have a small tank and the cool end reaches 24°C (75°F) when the thermostat is set to 28°C (82°F), lower the thermostat setting to 26°C (79°F). Ideally, the temperature at the cool end should be no higher than 22°C (72°F), especially during summer. If you have trouble keeping the tank cool during summer, you can try inserting bottles of cold water into the substrate at the cool end.
What humidity should hermit crabs be kept in?
New hermit crabs from a dry environment should not be immediately placed into a tank with high humidity. They need time to gradually adjust to the new weather in their tank. If you remember what humidity the pet store kept their hermit crabs in, then you should begin by maintaining the humidity at that level. If the pet store tank did not have a hygrometer and there is no condensation on the glass, then estimate the humidity to be around 50%. Every three days, increase the humidity level by 5% until you reach 80%. If the newly adopted hermit crabs came from a tank that was already at 80% humidity, then keep your tank at 80% humidity from the first day. You can slowly increase the humidity in the tank by adding more moss to the tank.
How do I calibrate my hygrometer?
Analogue hygrometers must be calibrated so that you interpret the readings properly. An uncalibrated hygrometer is as useless as not using one at all. To calibrate your hygrometer, try following the steps below. The method was derived from the About.com website.
Place the hygrometer inside a large re-sealable freezer bag.
Fill a mug with 1/2 cup of table salt and 1/4 cup of water. Stir the moist salt mixture for uniformity.
Place the mug inside the freezer bag with the hygrometer and seal it tight. Keep the mug and hygrometer a few inches apart.
Keep the freezer bag in room temperature and away from direct sunlight for two hours.
The hygrometer should read 75% humidity while inside the container. If it does not, then the needle of your hygrometer is not accurate.
Record the reading that your hygrometer gave you. You may want to perform this experiment from scratch several times for more accuracy. If your hygrometer reads 72%, then you will need to mentally add 3% to all readings that your hygrometer displays (72 + 3 = 75). If your hygrometer reads 80%, then you will need to mentally subtract 5% from all readings that your hygrometer displays (80 − 5 = 75).
What should I do if I adopt more hermit crabs in the future?
You should set up an isolation tank to separate newly adopted hermit crabs from your other hermit crabs. You can then keep the bedding shallow (see the next page for more details) and control the weather for the isolation tank without disturbing the hermit crabs in your main tank. However, this may be difficult to achieve if you only have one thermostat and heat source. Alternatively, you can wait until summer when the temperature is not an issue to adopt more hermit crabs and then just slowly increase the humidity for them. The newly adopted hermit crabs should stay in the isolation tank for at least one week before moving them into the main tank with your other hermit crabs.
Should I spray my hermit crabs with water?
No. You should only spray the air inside the tank with water to boost humidity levels. Hermit crabs may get irritated if you spray them directly with water. As mentioned previously, you can also boost humidity levels by adding more moss to the tank.
Should I use a fogger to boost the humidity levels?
Foggers are very difficult to set up without having them spit water everywhere and get enough fog out at the same time, so you are better off spending the money on a moss pit instead.