Disparate Temperatures

[Twovultures]

So, I have 3 ways of monitoring the temperature in my terrarium: A zoo med probe thermometer, a vivarium electronics V-100 thermostat with it's own probe, and an infrared 412L from Reptile Basics.

To say I am getting inconsistent readings would be an understatement. When the V-100 reads 81, my zoomed probe reads 85 even though it's stuck onto the EXACT SAME PLACE under the substrate, and my 412 is reading temperatures like 88! meanwhile, a mere inch above the substrate of shredded coconut, the 412 is reading temps in the high 70's.

I'm really worried about Wiggington's health-she's not moving when I disturbed her warm hide earlier (I had to move it so I could look inside without lifting it off of her, so she won't be disturbed in the future). Maybe she's just gotten used to her terrarium and is now less panicky, but what if she's getting sluggish due to messed up temperatures?

Does anyone know what's going on with my thermometers and how to solve this problem?

 

[Guruofchem]

Not surprised the above-substrate temp is that much lower, as heat can dissipate quickly through substrate. If you are hitting the glass directly with the IR thermometer, you may be going through the glass and hitting the UTH, which would explain its higher reading. Personally, I tend to distrust the standard ZooMed/Zilla thermometers generally - I suspect your other two methods are more accurate.

 

[Topazfyre]

For heating setups I actually usually put the probes outside the tank wedged between the middle of the UTH and the glass. This way I'm getting the highest possible reading and I know the corns can't possibly burn themselves. Also, if you're concerned about your snake being too hot, make sure the temperature gradient in the tank is also low enough, so one side of the tank goes into the low 70s or room temperature. So long as the heat isn't enough to cause her damage (and even a temp of 88 won't, though admittedly any higher might), she'll thermoregulate and move to the cool side if she's hot. If you see her submerged in her water bowl a lot and it's not shedding season, ambient temperature might be the reason.

Getting different temps based on location and device is really common. Guru made a good point about the substrate. You also have to keep in mind the rate of heat transfer of different materials. Since most thermostats work by turning the heat pad off when it gets too hot and turning it on when it gets cold, there's a temperature cycle going on. Depending on the thickness and type of material the probe is made out of, you may be getting a delayed reading (I know this happens for the ZooMed thermometer because of the thick plastic). You just have to work with it. Make sure the highest temp (the heatpad itself) doesn't exceed 87-88 on any reading and that there's a cool side of the viv, and your snake should be fine.

 

[Twovultures]

For heating setups I actually usually put the probes outside the tank wedged between the middle of the UTH and the glass. This way I'm getting the highest possible reading and I know the corns can't possibly burn themselves.

...This is so mind-bogglingly simple I have no idea why I didn't think about it. Thank you-this will ensure that the temperature doesn't get too high.

It's a pretty long tank (3 feet) in a very large room (a basement apartment) so it has a lot of cool space-about 65 degrees right now on the cool end. That is worringly cool, but I was nervous about turning up the undertank heater because of the different temperatures. Hopefully now I can get a better environment for my poor Wiggington.

 

[Topazfyre]

It's alright, it took me forever to figure that out, too, having the exact same problem you did. Especially since all the instructions say to put it inside....unch: I wouldn't personally wouldn't worry too much about the 65* so long as there's hides or even a fake plant halfway between the warm and cool side. Good luck!

 

[Twovultures]

All right, temperature is now down. The spot in the middle of the heating pad under the warm hide is 85 degrees, as measured with my infrared thermometer.

Temperature seems to drop off rapidly elsewhere in the tank, though. I found Wiggington on the cool end of the cage, which is still mid-60's. We're kind of in a cold snap here in DC, so I guess that the summer temperatures will soon mean that the entire room will be nice and warm, but I really am thinking of getting an OT heating bulb before next fall.

 

[Nythain]

As long as Wiggington has an ~85F area and a "however the hell cold it gets down to on the other end of the tank" area, he'll know where he needs to be when he needs to be there. Gradients, gotta love them.

 

[Nythain]

In other words... As long as you have a "long" tank, with a proper sized UTH (1/4-1/3 the length of the tank) at a regulated "warm" side temperature... The cool end temperature becomes near moot. There will be a gradient from your 85 end all the way down to however low the cool end gets. If the snake needs 70F and has hides available, he'll chill where it's 70F. If the snake needs 80F he'll chill where it's 80F. It would be preferable to keep the "cool" end in the 68-72F area, but if it gets colder, Wiggington just won't chill out there. The only truly imperative parts are proper UTH size and proper warm side temp.

 

[Twovultures]

Thanks. I guess it's good that I'm anxious about taking good care of my pet, but it's bad that I'm getting carried away with it. Best to just sit back and let her enjoy her set up. Anyway, I guess the temperature question is resolved-now, it's just a matter of seeing how Wiggington handles her first feeding

 

[Guruofchem]

These guys range all the way up into New Jersey, so they can tolerate 60s easily as long as there is a good warm spot.