HCA: Hermit Crab Association

Hi, all.

I upgraded my 2 PPs from a 10 gallon to a 29 gallon today, woohoo! Only trouble is, the temperature is not going above 74°.

I have a Ultratherm UTH that covers sub level all the way up that is covering 70% of the back wall & a second Ultratherm UTH covering top to bottom on one side. Both lengths with UTHs on them are insulated with a layer of aluminum foil & cardboard.

My lid is glass, but not perfectly fit. I currently have a towel double-folded along the back in case heat is drafting out that way. Reading temperature from an analog thermometer based on the ground & not against any of the glass.

Suggestions? My only thought is insulating the other side that has no UTH, but doubt that can really bump my temperature up by several degrees.

Can the thermometer be calibrated? What temp is the room the crabitat is in?

All I have is a narrow UTH along the back of a 55. With insulation board taped all edges and the hoods that came with the tank. And I can only get it 10 degrees above room temp without the lights on and without a blanket draped over the top slightly hanging over the sides.

With the blanket I can keep it 13-14 degrees above room temp at 65. At night when light is off. In the day when light on I can now leave the blanket over the top and it won’t over heat with my thermostat set on 82.

Edit: I have the sides taped w insulation board as well. I think the board is 1/2 inch thick.

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Maybe bump up the temp on your regulator. I've had to do that this winter.

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Xenocrab wrote: ↑

Sat Feb 01, 2020 11:06 pm

Maybe bump up the temp on your regulator. I've had to do that this winter.

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As in the temperature in the house? We keep it at 69° during the day and 66° at night. I am finding it hard to believe that with 2 UTH I can only get 5° above room temperature. :/

Me? I feel ok with 78-79 at night and 82 day. Is that ok?


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@craboloading That analog thermometer can probably be calibrated. Maybe it spun out of cal?

I’m having a hard time believing you can’t get temps up. You have covered more tank with heaters than I do and your room is warmer than mine.

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jrleath wrote: ↑

Sat Feb 01, 2020 11:16 pm

@craboloading That analog thermometer can probably be calibrated. Maybe it spun out of cal?

I’m having a hard time believing you can’t get temps up. You have covered more tank with heaters than I do and your room is warmer than mine.

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It read the room temperature right when I sit it out of the crabitat. And the coconut oil I gave them tonight has not turned liquid, which is would do at temps above 76°. I am so at a loss.

Are the heaters working?


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jrleath wrote: ↑

Sat Feb 01, 2020 11:23 pm

Are the heaters working?


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They are warm to the touch, yes.

Here’s might right now. You can see the insulation on the side which also wraps around the back and other side. Hope this helps


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74 is okay for hermits. It doesn't give a whole lot of cushion but they aren't going to be harmed by it.

I would give it at least a day to fully warm up before panicking. That much sand takes a while to stabilize.


I have a 29 gallon in my room, which stays between 55 and 65 degrees. The tank hovers right around 80 and I don't have to mess with it. I use two UTHs on the back, and have the back and top insulated with cardboard and aluminium foil to reflect heat back inside.

If you put a wet towel on top, will it increase humidity? I kind want to get mine higher. Also, if it did, would it be okay to use tap water to moisten it?

Crabby7Crabber wrote:If you put a wet towel on top, will it increase humidity? I kind want to get mine higher. Also, if it did, would it be okay to use tap water to moisten it?

I think if you put the towel directly on the mesh it will absorb more humidity once it dries out. If you have your lid saran wrapped first and then put a towel on top I think that might help more. This way the towel isn't in direct contact with the lid to absorb the moisture.

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CrabbyLover77 wrote: ↑

Sun Feb 02, 2020 1:25 pm

I think if you put the towel directly on the mesh it will absorb more humidity once it dries out. If you have your lid saran wrapped first and then put a towel on top I think that might help more. This way the towel isn't in direct contact with the lid to absorb the moisture.

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What about if I put it on top of a fuzzy bathrobe I keep on the mesh top?

Crabby7Crabber wrote: What about if I put it on top of a fuzzy bathrobe I keep on the mesh top?

Do you have any saran wrap on the top? If not, I would definitely wrap up the lid first as best as you can. That alone will help raise your humidity. Then you can use the robe or towels as insulation to keep heat and humidity in. Are you using any kind of heat lamps or just UTH? I'm only asking because heat lamps can zap humidity. Hope this helps some!

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