HCA: Hermit Crab Association

Hi there! I have just a couple questions that I don’t think are emergencies as my crab appears to be doing fine. This particular crab used to come up from underground around 10/11 at night, but I haven’t seen him in a while. I know he comes up because he causes a mess! I was just wondering if theres a reason his schedule changed, and if theres something I can do to bring it back to how it used to be. It would be helpful if I was still awake when he is, because I am trying to add more substrate in since I learned mine was not deep enough. I figure he will be okay if I add a little bit slowly every day, but I am still nervous to bury him too much. Also, an unrelated question is how deep should my water dishes be? Mine are the basic shallow ones right now, and he seems happy and healthy, but I’ve seen people with much deeper dishes. Do I need that? And if so, where can I find some? Thank you!!!
-Daisy

Water dishes should be deep enough for your crabs to submerge, but also have a way for them to climb out. Many people use the Rubbermaid type food containers, with craft mesh for climbing in and out. You can get them cheap at Dollar stores - and many people double them up, so when you take out the top one to change water, the second one stays in the sub and doesn't disturb any potential molters.
Yes, you are correct that you can add a bit of substrate every day, as long as you don't pack it down.
Crabs are strange, LOL, that might be the only explanation as to the schedule change.