HCA: Hermit Crab Association

We bought 3 crabs about 1 month ago. They came with their set up terrarium. We realized that the heat and humidity were way too low, so we have been working on that. We now have the heat up to about 80 and the humidity between 75-85.
All three of them stay under most of the time and are eating a lot less than they were in the beginning. We are wondering if it could be stress, they have been under since we got a bubbler. We turned off the bubbler temporarily to see if they come up.
We still want to change the substrate from dirt/moss to playsand/coco fibre. Should we do that now, or should we wait. We don't want to stress them out more, but the change in substrate would be good for them. The previous owners said that two of them recently molted so I don't think they are molting, but could change in environment encourage them to molt again?

Sorry for no response.

If the crabs are digging down under, that could mean they are de stressing. Destressing could take from a few days to a few weeks, so you will never really know when they will come up. With that being said, you should definitely wait on changing the substrate for the crabs. In case one of the crabs were to be molting, you could stress them to dangerous and deadly levels, or suffocate them with the substrate. It still wouldn't be good to dig the crab up even if they were not molting. You should wait until all three of the crabs are up.

When in doubt, just wait. I've been nervous because all of Christmas break, I only saw two of my crabs. I took care of them as normal and held off on changing the substrate. Well I'm home after two days of moving back into my dorm and a third crab decided to grace me with its presence. Maybe fresh from a molt, it's hard to tell right now without popping open my tank

As previously stated, better to wait. Let them de stress Congrats on your new additions!