Use a basin to raise it. It doesn’t matter whether the water is deeper or shallower, it will not drown. But it’s best if the water just soaks the shell. You can let it bask in the sun, just don't bask it in the sun for too long. You can use tap water, but it needs to be dried for a day before use. Crabs are omnivorous. You can feed them fish, whether it is raw fish or dried fish, they will accept it. You may also feed them fish feed, such as red worms, shrimp, snails, and clam meat. It is best to feed some grass-based food regularly, such as Vallisneria, Elodea, etc. As long as the feeding is OK, there is no need to worry about anything else. Crabs are easy to raise. But you have to take care of it carefully because it is injured and very fragile. With good care, the feet can grow back after several molts.