HCA: Hermit Crab Association

Hello! I have some molting concerns. I was gifted a hermit crab two weeks ago and I have never owned crabs before. My first crab Hermie was super energized the first week but once I put him into his properly set up tank he became lethargic and didn’t move a lot. He stuck to the back corner and barely walked around. Whenever I took him out of his tank he ran around and seemed happy until I put him back in his tank. I decided to get two more crabs to keep him company in case he was depressed and that seemed to have helped his energy level and he finally tried to climb something. During the two weeks he never dug down even when he seemed to be destressing. Yesterday I put tons of new shells in the tank for Hermie because his shell seemed a little small for him. This morning I woke up and he’d switched shells and was slightly buried. 20 minutes later I came back and he was gone. I assume he want too deep under the surface for me to see. I’m aware that he might not be molting, just digging around but if he is molting, I’m worried. Since I got him two weeks ago, he hasn’t eaten anything, and the only time he interacted with the water was when he fell into the saltwater pool. Unlike what I’ve read on here, he hasn’t bulked up for the molting and I’m worried he won’t survive without storing up food beforehand. Also, I didn’t originally purchase enough sand for 6 inches and I was waiting for more to be delivered when this happened. It’s about 4-5 maybe 6 in some places which I know isn’t good for molting. Is there a chance he’ll be okay? I know there’s nothing I can do now but I’m asking for my peace of mind.

Everything is fine. I have 3 medium-large crabs and they only eat like 1/2 teaspoon of food each night, crabs don't eat that much so he is eating it's just so little that you can't tell. The reason he doesn't seem so active is because they are nocturnal so when you pick him up he wakes up and that is why he is more active when you take him out. The substrate shouldn't be a problem as long as he can fully cover himself. Don't add the rest of the substrate until he comes back up. Everything will be fine.

Like FJ said, you often don't notice that they are eating, but they are. He could not have gone the whole two weeks without eating. Try not to worry too much.
You can add up to an inch of substrate per day, just don't pack it down. By adding a bit at a time, you will not collapse any tunnels.

Thank you for your advice! He has come back up after switching his shell and I’ve even seen him eat some popcorn!!!