hello i just picked up 7 red claw crabs to keep in my 90 gallon tank.Its in the tank alone with some fake plants a cave and 2 large bogwoods and just plain sand on the bottom.What kind of setup do these guys need? do they need land? if so.....can i make a large slope for them to get up too for surface air? or can i just lower the water level and make the bogwoods be alittle higher of the water line? Plus i researched online about how big they get but im not sure their size was ryt? So what are their actual lenght they can reach? What foods can i give to them?