UTH

[BettaCrew]

This is my current hermit crab tank set up. I will be adding more substrate today.
Temperature: 74-78 (cooler if home heat isn't on at 78+ = not economical and a tad toasty at times)
Humidity: 80-85

My main questions in this post are:

What size UTH do I need?

Where do I put it? (not on the bottom I realize). Do I place it so it is 50% above the sand and 50% below or 100% above the sand?

How do you get a UTH to not go over a certain temperature?

I can see covering the entire back of a 20-40gal; however, I don't think I really need to cover the entire back of a 250 gal aquarium. I think I might as well turn it into my living room space heater at that point. Haha. I want to put the UTH in the center behind the wood display.

Eventually I will have base rock to swap out for the wood in order to provide a change in scenery from time to time. I also want to add fake plants to the left and right of the UTH to hide the uppermost portions of it from view a bit (not dense or against the tank) as the tank is a foot from my dining table/living room and aesthetics are important as a result (picky I know... but that's the deal).

[Hermiesguardian]

Most of us put it just at the substrate line (it can overlap an inch) to the top of the tank. I would think just like for a smaller tank, you would cover the entire back. Someone else may say different. My largest tank is 90gal. My highest temp runs about 81°. In the winter with the sun shining on one end of the tank and the uth insulated. In the summer I remove the insulation.

[curlysister]

Personally, I am a fan of having multiple smaller UTH's. I have a 55gal tank, and have four: one on each side and two on the back, so that pretty much most of the space is covered. I can then plug them in/ unplug them depending on the season. (I live in Manitoba Canada where outside temps range from +40C in summer to -40C in winter, in an old farm house with no air conditioning; crabs are in a room upstairs that has a baseboard heater for winter heat.) This works really well for me! You can get thermostats that an UTH is plugged into, but I have no experience with those.

[BettaCrew]

Thank you for the replies! I found a link to UTHs from Reptile Basics Inc.

http://www.reptilebasics.com/ultratherm-heat-pads

Am I understanding correctly that it is best to be able to insulate the UTH? If so, these are able to do so safely.

I have a moss pit/shower caddy suctioned to the back and side of the tank. I'm guessing that placing a UTH on the opposite side of the glass is a no go? Would it be acceptable to just not have the UTH touching that section? How do I attach other things to the sides of the tank if not with suction cups if the UTH covers the entire back of the tank?

[Hermiesguardian]

Thank you for the replies! I found a link to UTHs from Reptile Basics Inc.

http://www.reptilebasics.com/ultratherm-heat-pads

Am I understanding correctly that it is best to be able to insulate the UTH? If so, these are able to do so safely.

I have a moss pit/shower caddy suctioned to the back and side of the tank. I'm guessing that placing a UTH on the opposite side of the glass is a no go? Would it be acceptable to just not have the UTH touching that section? How do I attach other things to the sides of the tank if not with suction cups if the UTH covers the entire back of the tank?

The uth goes on the outside of the tank. And yes, the ultratherm can be insulated. The ones you get in petshops can't.

[Motörcrab]

I really think a lot of heating has to do with where you live and how warm you keep your house. With you being in Texas you may be able to get away with less heating than us living further north. With my 75 gallon tank we use two Ultratherms, an 11 X 48 with a thermostat across the back, and an 11 X 17 on one side. Both are insulated with 5/8 thick Poly Pro insulation. Currently my house is 70-72 degrees I can keep the temperature in the tank between 82-86. In the summer I don't need the smaller heater.

So far the past two months I probably read a dozen topics here about people trying to raise the temperature. Usually it is because they are using undersized heaters for the size tank. Most of the time it's because they pick up the wrong size. I believe it's better to be able to add a thermostat to turn the heat off rather than scrabble trying to make it warmer later.

I think of heating a tank it as dressing for winter. If you go out in freezing weather in shorts you will get cold quick. If you dress in layers and get warm you can always remove a layer or put it back on when you get cold.

This is the care sheet that mentions proper UTH sizing.
http://www.hermitcrabassociation.com/ph ... 51&t=92457

This is what it has to say:
"These are the most popular option for warming crabitats. They are sold for reptiles for use underneath the tank, but in hermit crab enclosures the UTH should only be used on the side or back of the tank. Because of the need of thick substrate in crabitats, UTHs are not effective when used on the bottom and can possibly overheat and become a fire risk. Do not pay attention to the recommended tank size on the packaging - buy the largest sized heat mat that you can fit on the back of your tank as many store-bought UTH run too cool to heat a crabitat. Ultratherm brand UTH must be ordered online, but they are known to run the warmest and are capable of being insulated with styrofoam to boost the heat unlike many other brands. If the UTH runs too warm a plug-in lamp dimmer or thermostat can be used to adjust the temperature. Many crabbers prefer to use a pad that ends above the substrate line so that they do not have to worry about substrate drying out quickly. Also, UTH cannot be bent without damaging them."