Under Tank Heat Pads - UTH

[DonLisk]

I would like to begin a series of equipment threads that I hope everyone can contribute to.
For those reading this thread at a later date, I hope some of the gathered information is useful in your decision to select and properly place a UTH in your amphibians home.
This thread is in place to discuss the pro and cons of under tank heat pads.

Use of an Under Tank Heat Pad (UTH) is a common and useful addition for providing ambient heat and sometimes even humidity to an enclosure. Placement of the UTH is critical and will depend on many things including type of tank/enclosure, type of drainage, and even the type of frogs.

UTH pads are available in many sizes and from many manufacturers. They can be controlled with timers to set times when it will be on and off, and also be used with a dimmer to lower the amount of heat produced.
UTH pads were designed for use on the outside of the enclosure and not inside a wet humid environment.

Pros and Cons to placement:
A. Bottom Placement:
PRO - will add heat to a substrate and help burn off water in the drainage layer.
PRO - can add some humidity when burning off drainage water.
CON - can make the substrate too hot for a frog that burries itself.
CON - can cause a bottom to crack or fracture due to no airflow and over heating.

B. Side Placement:
PRO - will add heat to the ambient air temperature of a tank and create a cool side and a heated side to an enclosure.
CON - will not add to humidity levels but may slowly reduce the humidity with the dry heat created through the tanks side.
CON - depending on the pad's size, can create an area that is to hot at the glass surface and possible injury to the inhabitant that may decide to settle directly at the pads location.

Please feel free to add to or comment on the above information so we may create a localized place to research and decide on how one may utilize an Under Tank Heat Pad.

Thanks for your input.
Don

[Pandora3d]

i have a small UTH that i have placed on the bottom left side of my 10 gal. i was a little concerned about the possible stress fractures to the tank, but aesthetically, i just couldn't bring myself to stick it on the side. i keep the water bowl on the opposite side and that seems to be working out well as my toads can chose to stay in their hidey spots on the warmer side, or meander on over to the cooler side for soaking. i unplug the pad a couple hours before cleaning the substrate to allow it time to cool off so i'm not as worried about the drastic temps causing the glass to crack. and actually, i think i have a small enough pad that it doesn't generate a ton of heat, so i'm not even really worried about my toads getting too hot if they are right on top of it. i have noticed it definitely does keep the substrate on the dryer side, so misting daily is a must....but that helps me keep my humidity at better levels as well. so theres my two cents worth!

[DonLisk]

Pandora3d
What type tank are you using?
IE: Aquarium or pre-manufactured reptiles enclosure
I ask to determine if the pad is sandwiched between the glass and the surface the tank is placed on, or if air flow can occur under the tank.

Having a pad directly under a substrate with no drainage layer will cause the soil to dry out quickly, requiring misting for humidity to be done more often.
Are you using a drainage layer with this setup? If so, is it normally dry due to the placement of the UTH?

[Pandora3d]

i have just a regular ol' aquarium i used to have my fish in. it has little rubber 'feet' on the bottom of the tank, so there is plenty of space for air to circulate underneath. i do not have a drainage layer, but am contemplating adding a layer of gravel after my next cleaning. although i do not feel the UTH puts out much heat, and is not hot enough to harm my little guys, i'd rather not take that chance. i am looking at getting a new tank altogether as the 10gal is just too small for my liking after joining this forum and educating myself. if/when i do get a new one, i think i will still keep it on the bottom of the tank, i just do not like it on the side....and my guys seem okay with it on the bottom too.

[DonLisk]

Thanks for the reply Pandora3D.

To consolidate your input:
Your tank's UTH is placed on the bottom of one side of an glass aquarium tank and the tank is slightly lifted to allow airflow under the heat pad.
No drainage layer is utilized and the UTH heats straight to the substrate to generate heat on one side and a cooler area on the other.
Noticeable drying of the substrate occurs and misting is required to maintain humidity levels and to moisten the soil.
Size of your heat pad is small enough that it and does not generate overly heated locations for the inhabitants.

Again, thank you for the great information.

[sajane]

just a question about fire hazard or overheating.I have 14 pads on my cages, either on rheostats or thermostats so that should protect against overheating or power surges correct? I use another 5 pads on feeders without rheostats or thermostats. I have heard of a uth overheating and burning a plastic tub.but have not had any problems. Even the smallest pad will heat up to 110 degrees in my experiance with the temp gun.

[DonLisk]

Some great questions and something I have little experience with but have a good understanding of electrical wiring and fires.

Being a fire or safety hazard would depend on many things but since most materials would need much more heat to create a fire than 114 degrees, a spark would probably need to occur to ignite anything near the UTH.

I have never experienced any over heating issues with UTH use, but can see in some of my snake enclosures where the heat has left permanent burn marks right through the enclosures resin bottom. Whether this was due to no air circulation under the tank, or what was on top of the heated area, I can not say since it occurred long ago.

As for plastics, I believe that they can get hot enough to melt plastic if not air circulation is provided but still think it would not create a fire hazard only due to the heat the UTH is generating.