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Should I Leave the Heat Bulb on Overnight?

By: Dr Gareth Evans - Updated: 22 Aug 2020 | comments*Discuss
Heating Thermostat Lighting Bulbs Night


Do I have to keep the heat bulb for my bearded dragon on overnight or can it be turned off?

(Mr Anthony Roberts, 19 November 2008)


It really depends on the overall heating arrangement in your bearded dragon tank.

If your heat bulb is only providing a hot spot for basking and there are under tank heat mats, ceramic heaters, hot rocks or similar providing a general warm background temperature then, yes, it probably can be switched off over night. In fact there is a good deal of evidence to suggest that a night-time temperature drop can be very beneficial with a whole range of reptiles – especially if you’re hoping to breed. The idea behind it is pretty obvious really – come sun down, even in the tropics the temperature drops – so mimicking this in the terrarium allows animals to experience as natural a day/night cycle as possible. How much you allow the temperature to drop obviously depends on the animals concerned – desert temperatures plummet once the night falls, but for bearded dragons, around 5 degrees C should be about right.

However, if it is the only source of heat in the tank, then switching it off is more problematic and you might want to think about changing your set up to allow you to maintain the ambient temperature by other means, and only run your heat bulb during the “day”.

Environmental Control

Heating and lighting in the terrarium are two of the most critical elements in your pet’s environment and controlling them properly is a major factor in ensuring that your lizards do well. It’s worth investing in the highest quality of thermostat you can afford to control the heating system in your tank – dimmer-stats being one of the best kinds, especially if you’re using a spot lamp. These sophisticated bits of kit gradually reduce the electricity once the right temperature has been achieved, which avoids the “lights-on, lights-off” effect that happens with the older types of thermostats. It’s also gentler on the bulb’s element – which tends to make it last longer.

However, to achieve the best control over the environment in your bearded dragon tank, there’s nothing to beat the latest generation of thermostats, which will automatically maintain two different temperatures – one for daytime and one for night – which really makes conditions in the terrarium about as near-natural as you can get.

Just add a timer to your lighting arrangement – if you haven’t already got one – to control the length of the day and night, and your dragons will be well away!

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We have a baby comillion in a screen enclosure. What should the temperature be.
Deb - 22-Aug-20 @ 12:45 PM
Should I leave my heat bulb on all night long in my lizzerd tank.
Kickboxer - 21-May-18 @ 9:41 PM
Hi I have recently changed my viv from a 3 ft one to a higher viv n mre space in it I have a 60wtts heat bulb for it I have it on like 25 on the ministat is that ok in my old cage the heat light used to go on n off when reaches temp in cage now in my new cage the heat light is stayin on all the time can any help I have Tryed everythin many thanks x
Sarah - 19-May-18 @ 9:57 PM
Hi My tortoise has been tube fed for 12 months now he has hepatic lIver disease. He is fed 3 times a day the last feed at 11pm. He has been under uv infra red light during the day and under a moonlight during the night. Should he be under a light at night? My worry is that the food (oxbow fine grind) won'tprocess if he gets cold. Would appreciate your opinion. Thank you
Torty - 19-Dec-16 @ 3:23 PM
i have a corn snake and his temperature is fine during the day but on a night it seems to only be peaking between 13.6-14.7 and I'm a little concerned that its a bad thing please could someone give me some advice
craigw - 31-Mar-16 @ 2:22 AM
Mrs daniel craig - Your Question:
I have 2 baby Hermann both a month old,they hide in the night and cover themselves in the aspen bedding,I have heat and uv lights ,do I leave them on at night because they are babies

Our Response:
As a rule, at night adult tortoises require a drop in temperature and darkness, so bulbs should be turned off, as advised by the Hermann's tortoise care sheet, link here. However, just to be on the safe side, and because your tortioses are babies, you may also wish to ask your supplier directly.
ReptileExpert - 22-Oct-15 @ 11:30 AM
I have 2 baby Hermann both a month old,they hide in the night and cover themselves in the aspen bedding,I have heat and uv lights ,do I leave them on at night because they are babies
Mrs daniel craig - 21-Oct-15 @ 9:42 AM
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