Tub temps not getting hot enough with Herpstat 2 and Zoo-Med UTHs?

Okay. So I received my male Bumblebee yesterday, and due to my UTHs from LLL getting here quite a bit later than anticipated, I had to set up his tub the day I received him. I connected my large and medium (large for hot end, medium for cool end) Zoo-Med UTHs to my Herpstat 2, then adhered them to the bottom of my 31 qt. Rubbermaid tub with the temp. probes mounted in between the tub and UTH. Pictures:

http://i46.tinypic.com/6qjibl.jpg

Large UTH - shot from above

http://i48.tinypic.com/2ykdezk.jpg

Medium UTH - shot from above

http://i48.tinypic.com/2e1hzf9.jpg

Large UTH - shot from below

http://i49.tinypic.com/3fz4m.jpg

Medium UTH - shot from below

http://i46.tinypic.com/34imowm.jpg

Here is a picture of the interior setup

I'm using shredded aspen that's approximately 1" in depth. The issue I'm having is the UTHs are not getting nearly as warm as I need them to be. I've had to crank my hot side up to ~103 and my cool side above 95 on my Herpstat, but when I feel them, they only feel warm, and when I feel them through the tub, they're really not affecting the interior temps at all. Both these UTHs have raised the internal temps just 1 degree on each side. My ambient house temp is set at 70 degrees, so that's why I have another UTH on the cool side, but with the temps set like this on my Herpstat:

http://i49.tinypic.com/j62zo3.jpg

...it only raises the hot and cool ends to 73 and 72 degrees. WHAT?! Is there an issue with my temp probes, or is the substrate too deep? Is the Rubbermaid tub too thick? I'm stressin'.

First off your thermometers aren't reading the correct temperatures. UTH's don't increase the temperature of the air in the tub so your non-probed thermometers are 100% useless. You need a probe to measure surface temperatures.

Second a UTH will NEVER change the temperatures of the cool side, once again because they don't change air temps.

Your substrate is too thick as well. For a UTH to work properly the substrate needs to be no thicker than 1/2"

Quote:

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Originally Posted by The Serpent Merchant

First off your thermometers aren't reading the correct temperatures. UTH's don't increase the temperature of the air in the tub so your non-probed thermometers are 100% useless. You need a probe to measure surface temperatures.

Second a UTH will NEVER change the temperatures of the cool side, once again because they don't change air temps.

Your substrate is too thick as well. For a UTH to work properly the substrate needs to be no thicker than 1/2"

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Awesome! Thanks for your response. There's definitely a learning curve here for me with these UTHs, so they're taking some adjustment. I was under the impression that the UTH heat transferred through the material it was adhered to (plastic, in this instance), and the heat dissipated into the air, warming it...which is why I used a non-probed thermometer. Now the term "belly heat" makes sense. ;) D'OH. Glad I have a UTH for each side then! So I'll decrease the substrate thickness and get a probed thermometer...or two. Any suggestions for cheap probed thermometer buys? I couldn't find a probed Acurite at the Walmart I went to...

They do heat the object they are fastened too this is good for a degree or two maybe. Radiant heat sources like UTHs do not heat air.

http://www.ebay.ca/itm/Aquarium-Digi...ht_3879wt_1259

I like these ones they are not expensive and a number can be bought and checked against each other. They have twice the spec'd accuracy as accurites (+/-2ºF against +/-4ºF) I would suggest 5+ and then the comparison is likely to find the ones differing from the others.

It is likely that you are simply going to have air temp issues at 70ºF i would suggest raising the room temp to 74-5ºF this will assist a great deal in holding correct temps.

I guess I'm confused as to what you mean when you say "They do heat the object they are fastened too this is good for a degree or two maybe"...UTHs are only capable of heating the bottom of the inside my tub a few degrees? I don't need to heat the entire interior of the tub (all of the air), just the bottom inside, correct?

I raised my ambient room temp to 72 degrees, but I won't be able to get it to 74-75 before May, when the weather warms up here and the air condo comes on. Will I still be able to adequately heat my tub with 2 Zoo-Med UTHs and a Herpstat 2? Sorry for all the questions...I thought I had it all figured out from spending a good amount of time researching, but I guess I was wrong...

The uth are not going to raise your air temps. You need to find a way to increase the ambient temp. You might find a closet you can set it up in with a small heater hooked up to your tstat. You need to be as close to 80 as possible, low 70's is to low. If you can get your ambient to 80 you only need to use one uth for a hotspot of 88-90(that's what I like).

Also remember that what feels warm to you is usually to hot for your snake. The best way for checking surface temps is a IR temp gun. You should at least have a probe thermometer to measure it, like already suggested.

Your tstat will usually need to be set at a different temp than what is desired. My glass tank tstat is set at 98 and gives me a hotspot of 90. As long as you hotspot is correct you are good.

Anytime your dealing with tubs or racks you will have to increase your room temps. You can remove your cool side uth, and raise room temp.

Uth are a radiant heat source. (Same for rhp) the emit thermal radiation the thermal waves pass through air and water with out doing anything. When they hit a solid object they excite the molecules and generate heat.

The uth will heat the floor of the tub to until the thermostat probe shuts it off. The floor will in turn heat the substrate and that in turn heat the air. Follow?

The issue is 90 on the floor drops dramatically to the substrate and even more to the air. The end result is the most gain you should expect is a few degrees to the ambient air temps 1-2 maybe 3 on the outside. This still leaves you with an issue, at best your ambient temps will still be cool.

I would suggest a few degrees as a buffer. 75 being the coolest (constant) temp but I would add 3 degrees to be safe so 78 as a lowest constant temp ( short dips below are fine a few hours at 72 isn't an issue but a few days or more could become one.

The dual uth ( I run duals as well) hold the surface temps but make very little difference to the air temps. This means there should be a heat source that will directly heat air. Che or bulbs will do this, I don't believe Che are a good idea as they get crazy hot. This leaves bulbs the fluorescent light bulbs get warm with out extreme heat of tungsten. IMO safer. How to hook up something like this in a tub I am unsure of.


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A heat bulb will actually raise your ambient temp very easy in a tub. I found this when my cages were not delivered on time and had to improvise keeping my big blood in a under bed container.

Currently I have three young bloods that I ordered a rack for but with my luck the rack has been delayed for some reason so I have them in tubs sitting on a table with a heat lamp above which is giving me perfect ambient temps.

The only issue is you need a lamp stand because you can not place the heat fixture on the tubs. That and it looks silly. Overall it works very well though. For one tub it would be easy to setup.

Quote:

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Originally Posted by KMG

A heat bulb will actually raise your ambient temp very easy in a tub. I found this when my cages were not delivered on time and had to improvise keeping my big blood in a under bed container.

Currently I have three young bloods that I ordered a rack for but with my luck the rack has been delayed for some reason so I have them in tubs sitting on a table with a heat lamp above which is giving me perfect ambient temps.

The only issue is you need a lamp stand because you can not place the heat fixture on the tubs. That and it looks silly. Overall it works very well though. For one tub it would be easy to setup.

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You guys are the best...this is the most helpful forum! So when you say I need a stand, I would assume then I would place my heatlamp w/bulb on a stand situated 6-8" directly over the tub lid? It would penetrate the lid enough to heat the ambient temps, and your lid doesn't get too hot?