I am crabsitting two hermit crabs. When they arrived I looked on the computer for help on caring for them. The aquarium had leaves and dirt and dogfood,bread and corn flakes scattered on the bottom. I put gravel in the bottom though I am going to switch it to sand soon. I fashioned a plastic lid to hold humidity and gave them fresh water in a bowl. They had no food plate or water bowl. My wife went out and picked up a under the tank heater, crab food, sea sponge and sea salt. The salt is Morton's coarse sea salt w/out Iodide is this ok to use? I gave them fresh fruits and they liked the grapes. I want to buy a humidity gage and a true lid. Kind of an expensive baby sitting job. I am suprised they were still alive after reading this forum. Thank you for any help.