Under-tank heater question

[DannyA]

I just bought an under-tank heater to increase the temps in my BP's tank and give him some more heat at night especially, so I want to use it right. My first question is, do I need a substrate, or will just having newspaper be OK? I don't want the tank to crack or anything, so that's why I'm asking. Also, has anyone here taken the "side of tank" approach? Will that be better for warming the tank? He hasn't eaten for 2 weeks and I have determined that it is almost certainly due to temps, because he is active and otherwise healthy, so I want to maximize the effectiveness of the heater.

[bigballs]

i would suggest putting it underneath the tank. but first describe your setup. tank size, other heat sources, amount of hides, temperature and humidity levels... stuff like that.

[JLC]

It should go UNDER the tank....and newspaper is fine. But what you need to keep it from getting too hot is a thermostat. Or at the very least, a rheostat (dimmer switch).

A thermostat is ideal because you set the temperature and it keeps it just where you want it all the time. You can find safe, reliable ones at reptilebasics.com.

A rheostat simply "dims" the amount of power going into the heating pad so it doesn't reach its max heat...you have to really play with it (with a thermometer in the tank) to make sure you get the temperature right...and then it will fluctuate with changing room temps. But if the area that the tank is in maintains a steady ambient temperature 24/7, then a rheostat is a decent (and much less expensive) alternative.

[FL0OD]

I totally agree with JLC. You have to regulate that heat. If you need something right away and the pet stores near you does not carry that dimmer try Home Depot and grab you one of these. When I first went looking for dimmer I had to have one like that day and none of the local pet stores to me carried that rheostat, ReptiTemp Rheostat. You would think it was a basic item but I came to find out it was much more of a pain to find. That first one should cure your problems if you cannot find the other item.

[giaach]

Actually I messed around with a rheostat and found that while it doesn't allow as much power to the UTH. It will eventually get to the hottest temp which in my experience is around 115. Basically by dimming the UTH it just takes longer for it to get hot but still gets to its highest temp. SOOO I would def suggest getting a thermostat. There's a nice sticky in Husbandry that shows a glass tank set-up.

[DannyA]

Thanks for the replies. Tank is a 20 gallon with a heat lamp and hide box on the cool side, newspaper substrate, and water bowl, obviously. I have not put in a hide box for the warm side because he just slithers his way under the newspaper when he wants to get warmer. The temperatures aren't warm enough (80ish on warm side) so I got the UTH. Next on the list is the thermometer, which I have to get still. So I need to get something to regulate it? I was led to believe that the UTH's were superior to a heat rock in that they don't get too hot, maybe 100 degrees. Sounds like a classic case of a petstore trying to sell a product.

[starmom]

Thanks for the replies. Tank is a 20 gallon with a heat lamp and hide box on the cool side, newspaper substrate, and water bowl, obviously. I have not put in a hide box for the warm side because he just slithers his way under the newspaper when he wants to get warmer. The temperatures aren't warm enough (80ish on warm side) so I got the UTH. Next on the list is the thermometer, which I have to get still. So I need to get something to regulate it? I was led to believe that the UTH's were superior to a heat rock in that they don't get too hot, maybe 100 degrees. Sounds like a classic case of a petstore trying to sell a product.

No; they get too hot!! However, RBI has one that Rich writes does not need a t'stat: "Ultratherm Vivarium Heaters have been manufactured in Scotland for over 20 years to exacting European Standards. UL Listed component.
These pads can often be used WITHOUT a thermostat due to their low wattage density. The element is similar to the Flexwatt heat tape but it is a far more durability...". The web site is: http://www.reptilebasics.com/Ultrath...p-1-c-273.html
You could call or email him for the particulars; I have not used this product, though I might one day...

[bender29]

Actually I messed around with a rheostat and found that while it doesn't allow as much power to the UTH. It will eventually get to the hottest temp which in my experience is around 115. Basically by dimming the UTH it just takes longer for it to get hot but still gets to its highest temp. SOOO I would def suggest getting a thermostat. There's a nice sticky in Husbandry that shows a glass tank set-up.

That is not true. A rheostat doesn't slow the transfer of power to the UTH, it cuts it. It essentially is a manual form of a proportional thermostat. Theoretically, if you have the rheostat switch set directly in the middle, the device should be using half the power it normally would. A rheostat controls how much power the device is allowed to use.

What your seeing is probably your ambient temps rising throughout the day, which in turn will cause the heat/temperature to increase. In this case you would have to adjust the rheostat to compensate for the higher ambient temperatures.