HCA: Hermit Crab Association

Ever since I upgraded to the larger 55 gallon tank last year, my crabs take turns going under and molting. Having all 5 up at the same time hasn't happened. While I think its great that they are taking turns and sharing LOL it has become problematic for me. I am in the process of pulling out the old pools and putting in new ones that hopefully will be more manageable. I am using Wolfnipplechip's idea but using two sets of pans so that the bottoms can stay in and not disturb the sub while I am cleaning/refilling the tops. Anyhow, pulling the old pools means I need to add more substrate because the new ones are not as long or deep. As long as its the right consistency, any crabs under should be able to tunnel out of the substrate I am adding right? I just don't want to inadvertently trap any that may be down under. My husband suggested relocating them into the 10 gallon until I have all 5 out but that could take months and that means operating both tanks. Any suggestions?

Will removing the old pools disturb a lot of substrate? That would be my only concern, if they go down into the sub very deep removing them may collapse tunnels/caves. Otherwise, just carefully add prepared substrate a handful at a time to deepen it. As long as you don't pack it down it should be fine with crabs under.

I don't think they are down in the immediate vicinity of the pool and when I pulled the freshwater pool and replaced it with just a water dish all of the substrate stayed put until a naughty crab (see profile pic) decided it would be fun to slide down the indent before I could fill it in. Usually they burrow down in the middle of the crabitat and the pools are on the sides. When the first pool came out, Penelope was down and I worried that the sliding incident might have collapsed her tunnels but then she reappeared the next day and the following day Sebastian disappeared to go down. Thats why I figured I would check before pulling the second pool. These crabs can be very noncooperative when remodeling is going on.