# Temperature question



## Jess (Sep 20, 2009)

Hello,

My husband and I have had our tegu for 2 months now. We originally had him in a 20gal long but now he's in a 75gal. We're using a 160watt mercury vapor bulb but's the temp in there is only getting to about 80 degrees. That's obviously not hot enough. Does anyone know where I can get a bigger wattage bulb? I've done some searching and it seems like that's as big as they come. Any suggestions would be great.


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## cornking4 (Sep 20, 2009)

160 watt is definitely large enough to do the job, it's most likely that you're just keeping it too high above the basking spot. I use a 100 watt for my 6 foot by 3 foot cage, and it does an outstanding job of keeping it at a constant 105 degrees fahrenheit. How high is it from the floor of the enclosure?


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## Jess (Sep 20, 2009)

I just measured it and it's about a foot and a half high. Maybe because it's cooler downstairs? We don't have the space for it upstairs.


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## Bubblz Calhoun (Sep 20, 2009)

_You can also try covering the rear and the sides of the tank since the glass doesn't hold heat too well. I don't know what kind of cover you have on it but covering half with foil (if it's a screen top) or something (non flammable or wouldn't melt) would also help with heat and humidity. 

By the way,..for the temps you're reading at 80*F is that just an inside temp or is that directly under the light? Because they should be different, there should be a cool side but the temps under his light should be much higher._


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## cornking4 (Sep 20, 2009)

A foot and a half is far too high; little or no direct heat can reach your basking tegu at that height. The appropriate range is usually 8-10 inches above the substrate, depending on the size of your tegu. the goal is to keep the light about 4" above your tegu while maintaining a temperature of about 110 degrees. I can accomplish this with a 100 watt, so you should definitely be able to accomplish it with a 160 watt.
I realize that you are probably setting the light atop a mesh lid of a glass enclosure, which, I'll admit, is the setup that I used before I moved to a larger, permanent enclosure. To attain the correct temperature with this setup, it is often necessary to provide an easily accessible, elevated basking rock. This should allow you to control the basking temperature much more easily.
I also would like to recommend that you begin thinking of building a permanent 8'x4'x4' cage for him soon, as he will soon outgrow the 75 gallon and building a sloppy, last minute cage is never good. You can find a wealth of information in the "Housing" forum, where many people post pictures and don't mind if you borrow their ideas. These style cages allow you to pick up your tegu without the feeling that you're "looming over them", which reduces stress. They also allow a light to be hung from the ceiling, which can be easily adjusted up or down for the perfect balance.


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## mikecrowder23 (Sep 20, 2009)

Also uvb disipates quickly with distance so no more than 12" from the basking spot to ensure that he reptile gets the uvb it needs.


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## MIKE-ZILLA (Sep 20, 2009)

> To attain the correct temperature with this setup, it is often necessary to provide an easily accessible, elevated basking rock


 this should fix the problem. but if it doesnt you may have to add another basking light or heat the downstairs room a little more.


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## dragonqueen4 (Sep 20, 2009)

the 160 mvb are not hot enough for a 75g tank, your going to need a second bulb, not a mvb, just a regular heat lamp and position it right next to the mvb on one side of the tank, so theres still a warm side and a cool side. with most mvb's the uv output is too powerful to position the bulb any closer than 18inches away from the animal or else youll sunburn him


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## laurarfl (Sep 21, 2009)

Ditto, the MVB should be fine at 18". The issue is probably the ambient temperature of the room. But first, what are measuring the temps with and where are you measuring? Covering the screen top to prevent heat from escaping will help. Providing a flat rock under the light for smooth, warm basking spot will help, too. But it sounds like you probably need to add an additional heat source on the basking end. You can add another heat lamp or a ceramic heat emitter.


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## Jess (Sep 22, 2009)

Thanks for the useful information, I appreciate it. My other concern is, since he's been in the 75 gal, he doesn't bask. He's only about 3-4 months old. When we had him in the smaller enclosure, he'd bask off and on all day long. I'm considering putting him back in the smaller enclosure until he grows more. I'm wondering if it's too much for him b/c he's still a baby? I just want what's best for him.

We do have a temperature gauge in the tank, as well as a humidity gauge. 

I'm so glad I found this site.


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## cornking4 (Sep 22, 2009)

Tegus are very similar to babies in the way that if you change their surroundings, they're not too happy about it. Just when I moved Zzyzx's waterbowl to the other end of his cage he refused to eat or come out and play for a few days... They definitely get grumpy about this. When they're younger, it doesn't matter quite as much, but try to keep the enclosure changes to a minimum, and get him into a permanent enclosure ASAP. Because their enclosure is their one safe place that they can feel secure in, messing with it is not recommended unless it's absolutely necessary.


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