Compiled by Vanessa and Marie (aka ladybug15057)
There has been a lot of false information when it comes to hermit crab care over the years. One of the biggest known factors of land hermit crab deaths is dehydration from the use of desk lamps with a common household bulb, coupled with wood shavings as substrate in a plastic ‘kritter keeper’ with vented lid. Before Under Tank Heatersor thermostats were made available to the public, many hermit crab owners were advised by pet stores to leave the desk lamp on overnight to help keep the chill of dropping temperature at bay. Desk lamps have been proven unsuccessful at meeting the needs of land hermit crabs as a primary heat source, resulting in fatality, especially when coupled with wood shavings as a substrate in an enclosure where any humidity escapes through the vented lid.
If you use an Under Tank Heater which covers half of the dimensions of the back of your tank as the primary heat source, you may not need the lamp as a heat source. However, your hermit crabs may benefit from a UVB bulb (certain species such as perlatus need more UVB than other species). You may be still want to illuminate the tank overnight with a moon glo bulb so that you can watch the activity in the food dish or stare wide-eyed during a seashell swap. The only light recommended for night viewing is a moon glo bulb that simulates the glow of the moon. Perfect for our hermit crabs who are more relaxed eating, climbing and swapping shells beneath the gentle light, which gently illuminates your crabitat. You will be amazed how much more active they will be with the extra warmth. It is my personal choice to use bulbs no higher than 40 watt, with 25W for a small crabitat. Others have chosen higher wattages to warm their larger (100 and 120 Gallon) tanks. It is important to take the size of your crabitat, substrate type and other factors before deciding upon your lighting needs. It is very important to monitor the air and substrate temperature as well as the humidity level of the crabitat.
Some bulbs are of the ‘Edison Screw’ type, and require a lamp such as Zoo Med Deluxe Porcelain Clamp Lamp
or a Reptile Hood/Strip fitted for edison screw bulbs. A 15 Watt bulb can be used for lighting purposes, however the ambient (air) temperature may rise 1-2 degrees. With higher wattages you may notice a problem with keeping the humidity within the 70-80% range. Many hermit crab owners have chosen to add a reptile water dish or have installed drip systems, timed misters, or waterfalls to keep the humidity level from dropping. You must be vigilant when using any water systems as a failure in the system will flood your crabitat and put your molters in danger.
It is important to keep a close eye on both the humidity and temperature within your hermit crab’s enclosure, and to provide an environment that will put your hermit crabs at ease as well as keep them happy and healthy. Investing in items such as under tank heaters, moon glow bulbs, hoods and possibly thermostat or rheostat to regulate conditions and your hermit crabs will have a higher chance of survival when Summer leaves us and cooler days approach. Left without adequate heating and humidity would usually result in lowered activity. hibernation and perhaps fatality. While a desk lamp may seem an economical solution, I’m sure you will agree that the death of a loved hermit crab is too high a price to pay.
For some ideas on the different types of lights you can use check out our Methods for heating your hermit crab tank article.
Note: As with heat from an under tank heater, it is highly recommended that a thermostat is used.