I need advice on a heating mystery!

[Drew1405]

Hey guys, I'm a newbie to this forum and to reptile keeping in general. I just got a Crested Gecko a month ago (my first reptile) and I am getting a Bearded Dragon in a few weeks time.

In preparation for getting my dragon I have been setting up a vivarium so that it is all ready for the dragon to go into. However I have come across a very strange situation with my heating.

My vivarium is a medium Vivexotic which is around 3ft long. I installed a heatlamp at the right hand side so that this would be the hot end, and the other end the cool end. I have a UVB striplight mounted to the wall at the back. My heatlamp is a Repti-Zoo metal dome which sits on top of the viv and I have cut a hole in the roof of the viv, the same diameter of the dome, to create the basking area. I have a 60w basking bulb inside the dome.

I purchased an Exo-Terra digital thermometer and was testing it out with the lights on. I put the probe on the bottom of the viv at the cool end and got a temp of around 25c. I then moved it to the hot end and got a temp of around 35c. I then bought a 2nd thermometer (same as the first) and installed both into the viv properly. The probe at the hot end is on the roof a few inches from heatlamp. The probe at the cold end is also on the roof.

Here comes the mystery... as now my hot end is reading temps of around 30c and my cold end is reading temps of around 35c!

Does anyone have any idea how this could be possible? Or is my 2nd thermometer somehow defective? I don't know what action to take next as I obviously want to have my viv sitting fully prepared and correct for when I get my dragon.

 

[Momomo]

when you say you put the thermometer on the roof, I am guessing its the top of your viv, where the lamp sits? I think the top cover of your viv is getting heated from the dome, although I am not sure why the cold side would be hotter. Anyhow, there is no sense measuring temps on top of the vivarium.. You need to place the probe ON (not near) your beardie's basking spot to measure the proper basking temp. For the cool side you can either probe the floor or whatever furniture you have in there.

 

[Drew1405]

when you say you put the thermometer on the roof, I am guessing its the top of your viv, where the lamp sits? I think the top cover of your viv is getting heated from the dome, although I am not sure why the cold side would be hotter. Anyhow, there is no sense measuring temps on top of the vivarium.. You need to place the probe ON (not near) your beardie's basking spot to measure the proper basking temp. For the cool side you can either probe the floor or whatever furniture you have in there.

Would it be ok to have the probe for the cold side "under" the substrate? Or should I just locate the probe on the back wall down as low as possible?

For the hot side, my probe is stuck to the inside of the roof right next to the heat lamp. Should I just move that down as well? Directly beneath my heat lamp I have a branch for the dragon to sit on. The closest I could get my probe to that would be to stick it to the right hand side wall down at the level of the wood which would be probably about 5 or 6 inches away from the side.

 

[Momomo]

What substrate are you using? I think for the cool side, sticking it to the back wall will be fine. But for the hot side you need to measure directly on that branch where your dragon will sit. In my opinion, and some people on this site would probably disagree, it is not necessary to have your thermometer in there all the time.. For the first week or two maybe yes, it will be easier to monitor temps with the thermometer always there, but I honestly don't check the temps more than once a day anymore because its pretty much always constant during the day..

 

[Megan1961]

Easy way to figure out the problem is to buy a temperature gun from home depot! They have some around $30 and it is well worth the money.