UTH on very large terrarium?

I'm in the process of setting up a 55gal terr., which is something like 1 x 4 ft, and given the weight that will be in it, I'm a little concerned about using a UTH and those tiny little dots that come with it to space the tank up. I use a lot of natural rock, and I'm thinking I might just have to stick to light heat. Can I use a wall- mount UTH? What do you all think?

Belly heat is what Leos need for digestion.

Maybe you could get some small blocks to put on the corners and the sides to lift it just a little.

Hi there!

I can assure you, you do not want a tank that heavy sitting directly on the wiring for a UTH. Just the weight of the tank alone will pinch through the wiring's insulation. Any vibration or motion will just speed up the process. I would get some pieces of 1"x2", four actually, and lay them under the tank to keep it up off the wiring.

When you say you use a lot of natural rock, what size and how much do you use? If you've got a 1/2" layer of pea gravel, then the UTH will heat through it, but it'll take about a day for it to get to temperature. If you're using gravel larger than that, or a thicker layer than that, I think you'll have problems attaining the temps you want.

Personally, I'd go with about 1/2" of sand. That's what I use for my beardies, and the flexwatt heats through it no problem, gives me a nice steady 85degree surface temp.

I guess I will go with the 1 x2s. I'll be using a bottom layer I think of 1/2 inch or so slate tile, plus climbing structures of varying rocks. I get pretty good belly heat with those and some good lamps, so I may just stick to that. What do you think of those wall mount UTHs?

Wall mounting the UTH won't be useful. You'd get a little bit of radiant heat, but most of it will go up (heat rises), so it won't do your geckos much good.

I don't think you'd have any problem heating through 1/2 slate with flexwatt though. It was originally designed as floor heating for houses. If you were using gravel that didn't pack together well, and had lots of airspace between it, then you'd have a problem getting heat because the gravel would act just like insulation.

The only drawback I can see is that the slate might take a couple days to get to temperature and you won't be able to cycle temps or allow for a nighttime temp drop. But if you're going to leave it at one set temp all the time, it should work perfectly.

Could you tell me some more about this flex watt stuff? Is it the same stuff they use for like radiant floor heat under bathroom floors? Where would I get it, and how much would I be looking at for half of that size tank? I can still get a slight night temp drop just with light cycles, and maybe I could put the flexwatt on a timer? I'm wondering if it might be easier to skip the under tank heating altogether. And I'm thinking a wall monut UTH could be used to heat substrate if I mount it at the bottom and use my usual several inch layer of substrate. I sometimes wish I understood thermodynamics better!

flex watt is very very inexpensive. For 11" wide it's usually $3.50 to $4.50 a foot. It does need to be wired, which requires a little skill or a willingness to spend about 10 to 15 minutes learning how. There some companies that will sell it prewired. You can find several internet companies that sell it and it is always at reptile shows. You can use it wired to a dimmer switch but it is safest to use a thermostat, which is the same for an UTH anyway. The cheapest Thermostats are around $30. I love flexwatt and use it on all my enclsures.

Originally Posted by geckogrl6

Is it the same stuff they use for like radiant floor heat under bathroom floors?

That's exactly what it is!

for a 1ft x 4ft cage, all you'd need are two pieces of 11"wide x 12" long. It comes off a roll, so the pieces will come connected. And as Bob says, there are several companies that will wire if for you for $8-10 when you order it. Prices are around $4 per foot for the 11" wide Flex.

You will need a thermostat to regulate it though. Flexwatt can get very hot, as can any other type of UTH. If you go with a proportional t-stat (Helix or Herpstat) some of their models are programmable for night drops. If you go with an "on/off" type t-stat (Ranco or Johnson) you can put them on a timer to allow for night drop.


Edit: Here is a link to the manufacturer's site http://www.calorique.com/Products.html

And how many inches of substrate can I use? It will stick to the bottom of the tank? Can I put it inside the tank if I'm using a thermostat?

You tape Flexwatt to the bottom of the cage, on the outside. It isn't adhesive itself, so you'll need foil tape to secure it. It's just that, metal foil tape. Most places that carry flex sell foil tape as well. Or you can go to Home Depot and get a 50ft roll for about $3. You need to use it because it's the only tape that will withstand the temps of flex.

How much substrate again depends on what kind of substrate. I've got about an inch of play sand in the beardies cage, and it heats that up no problem. I could probably go up to 2 inches without having a problem getting the temps I want. 1/2 thick slate should heat just fine, as long as one side of it is flat so that there aren't air gaps between the glass bottom of the tank and the slate. That'll cause uneven heating because the air will actually insulate the slate some.