HCA: Hermit Crab Association

i have this air pump a pump divider and some tubing and this section of a book shelf and i want to know if i use the divider cut the tubing in half mount the book shelf and put the pump on that (no check valve incase of power outage, good one anyway) feed the tube into the two waterdishes for bubbling pools will the crabs be able to hurt anything or will the tubing be able to get snipped or hurt them?

Adding movement to the crabs' water dishes is great, even though you do have to refill the container often, but it keeps nasty bacteria that forms in stagnant water away. I would try to attach the tubing to an airstone, or weigh it down with something because then the tubing will just float to the top, and feed air into the tank. The bubbling will also give of a lot of humidity, which your crabs will love!