Lowering temperature?

[Epiphile]

Were you able to get the new room temps? I'd be useful to know how much of a differential there is.

[froggsong]

It still seems VERY odd that your temps in the tank haven't fluctuated if you've added fans, cooled the room, etc etc... You say it is "still" 90 degrees with the lights off, is it higher than that with them on, or is it the same?

Is the tank a glass tank, or is it made of something that insulates better? Glass is soooo inefficient at holding in heat. Without something heating it (like your lights, a heat mat, etc), it should be, at most, a couple of degrees higher than the room temp.

Are there other sources of heat around the tank? A heater vent behind, above, or underneath? A window that gets alot of sun? Does the wall that backs to the tank have anything hot in it or on the other side of it; like your fridge, oven, hot water heater?

Do you have another thermometer that you are SURE is reliable that you can check the temp with? I'm assuming when you said the battery was fine, that the temps were the same with a new battery. That doesn't rule out a calibration issue or a simple malfunction. For example, I have some thermometers that I had to retire because they were reading hotter than what the temp actually was, even with fresh batteries (this was a big problem for me, as I was keeping my CWD nearly ten degrees too cool, ALL winter). I bought a new thermo for another tank, compared all of the thermometers with their probes in the same glass of water, and the old ones were way off. Even the humidity readings were wrong. I've also had a couple of new meters that I've had to return because they weren't reading properly.

I know this must be terribly frustrating for you. Glass just shouldn't be holding in heat that way. Now, with a wooden tank you can expect your inside temps to be higher than the temps outside, even without any supplemental heating. Wood just insulates well. But glass? It's generally COLDER in my glass tanks than the room temp, unless I'm heating them. It's one reason why I don't like using glass tanks that much...

This is a conundrum, my friend... Perhaps a couple of pics of the tank and the room will help us point out the culprit.

[beckdg]

i absolutely agree with everything froggy said except not too sure about a tank being cooler than a room in most cases. evaporative cooling would be the reason for a glass tank being cool. glass is one of the top materials likely to display evaporative cooling. if there's nothing to evaporate a glass tank should still be warmer than the room because of the light bending effect and the insulative properties it does have... but not by much unless it's receiving direct sunlight... or something else that may be overlooked.

one thing that doesn't seem to have been visited is the type of batteries you're using. many thermometers (especially the cheaper quality ones sold for pets at premium prices) are very picky about voltages and/or amperage. this can make a thermometer completely haywire in the event you happen to purchase batteries that have been on the shelf for a while or are a bargain brand. i would definitely use energizer or duracell batteries with a recent production date (where the shelf life has quite a bit of time left).

one thing that could definitely help is a cooking thermometer. even the cheapest ones should be pretty close in accuracy for liability purposes. (no company wants to risk a large law suit over a $2 thermometer, it's just bad business) if you have one that reads down to room temps you might monitor the room and tank back and forth for a few days.

i agree with the pics and i'd also like to see some details on the hood you built too.

[TPG]

Problem solved!!! It turns out that the meter was bad after all. Even when the batteries were changed out twice it still read wrong. I purchased two other meters to compare to the Exo Terra which was in the tank. The room temperature read 72-74 degrees on both meters. After I tried them in the tank they read about 75-76 degrees. The original Exo Terra meter still read 90 degrees after sitting in the room for about 2 hours. Thats's the last Exo Terra meter I buy.

The tank is glass. The back and left side of the tank has a background added (I made the background using the greatstuff technique), which may add a bit of insulation for heat. The tank is possitioned against a blank wall without vents or any kind of heating or cooling devices around it. The other side of the wall is the outside of the house.

The tank is well established now and I can finally order the frogs. I'll add pictures once I have them.

Thank you guys for all of your support and help, I really appreciate it a lot.

[beckdg]

i guess we can stop beating our brains then, lol.
we have come up with a bunch of stuff to answer later questions and things to look out for though.

now just do us the favor and don't lose those batteries after our combined efforts. you might need them soon.

[froggsong]

I don't really like exo-terra stuff all that much myself...

I'm glad you got the problem fixed.

[Epiphile]

Yes, glad to hear it worked out.