HCA: Hermit Crab Association

Hi everyone,
I am excited to start this journey. So I am a new hermit crab owner - 2 purple pinchers. I am using a Exo Terra terrarium with a mesh lid (18x18x24). The humidity is fine but I do have problems to get the temperature up. I thought I did prepare myself well enough - read tons of books and actually a lot on this forum. But it turns out I do have a ton of questions. Surprisingly both of my local pet stores do sell hermit crabs but give very conflicting advice on care - especially the heat question. One told me to put a heat pad under the substrate (did not do that expect for a few hours at night) and the second one does not use any heat pads but an overhead lamp (also read that this is not a great advice). Well the first night I used the UTH (10-20) gallon on the outside side of my tank. I realized that it got waaaay to cold at night (under 70 on some spots). So I switched the one under the substrate on to make it at least bearable. One of my hermies dug right under when I put him in but was out at night - I have seen him close to the water and there was sand in the water, so I guess he was in. The second one is not good - has barely moved and dropped some limbs. Not sure if it can be saved.
So today I realized that I have to take matters in my own hand and did some further research - on this forum actually. I have currently a heat pad on the back of the glass covering about 75% right above the substrate (coconut fiber/ playsand) and a second on the side (same corner). The heat has gone up to F78 but the opposite corner has F70. I wonder if that is ok for now as they need gradual temperatures. Should I cover the mesh lid with some ceran wrap or cardboard? Any advice is welcome - thanks!
Dodo

Don't put a UTH underneath the tank, or it becomes a fire hazard. Back and/or sides of the tank only. Depending on the brand of heat mat, some can be insulated over top - what brand do you have? If you can't insulate over top, you could insulate around it.
The reason to put plastic wrap )or some other non-porous material like plexi glass or glass) over the mesh lid, is to hold in heat and humidity. What is your current humidity reading?
How deep is your substrate?

Hi there,
thanks for getting back to me. I do have a substrate mix with coconut fiber and sand, it is about 5 inches deep. The crabs are really small and I think that should be deep enough. The humidity seems fine around 80% - at the heater less but I do mist the surface regularly. I have ceran wrapped the lid now and put a towel on top. I am more concerned about the temperature. I have two gauges in - close to the heater and on the opposite corner. Both read in the low F70 what seems not enough. I have this brand
https://www.petsmart.ca/reptile/environ ... hod=Search
I have two of those... one covers 75 % of the back wall of my tank. A second smaller one is on the side of the tank. Any other ideas what I can do to get the heat up?

That type of UTH cannot be insulated over top. But you can insulate the areas of the tank that don't have the heaters on them. And you can add more insulation to the top, like a folded up wool blanket. You could add another one of those UTH to the other side, or consider getting another brand that you can insulate over the top - there are other brands that warm up a tank better than the Zoo Med (the ones from Bean Farm).

Thanks for the quick reply. I have folded up a blanket over the top a d will see if that works. Do you think that a constant temp of low 70 is bearable until I get new mats?

Also I know that new crabs need to festrede but I am not sure if they had any water or food since I got them on Dec 26. is that normal?

OMG autocorrect ... destress

For PPs, 72 to 85 F are safe temps. You can try insulating parts of your tank that don't have a heater - it doesn't have to be anything fancy, tinfoil wrapped around cardboard will work.
Crabs eat so little when they are small, that you may not notice. I swear for the first couple of years I had my crabs, I took out the same amount of food that I put in. The only way I knew they were eating is because they were alive! Just keep offering a healthy variety of foods, and they will take what they need.

Ok! I will try the tinfoil wrapped around cardboard trick and see if I can get the temp up a bit. I assume it's normal for them to go down when they come new into the tank?

Oh yes, crabs will often go underground to de-stress. Or if it's been a while since they had deep enough substrate to molt, they will go under for a molt right away.

Thank you curlysister for all your valuable help. I did insulate parts of my tank that did not have a heater with tinfoil wrapped cardboard and it keeps the temp stable at F72 but I don't get it higher. My two crabs moved in the tank on Dec 26 - one is sitting under the hideout, the second was out once in a while but is buried again. I guess the destressing phase can last for a while?