Since most crab tanks are one level, and hermit crabs mainly use the surface area of a tank, is a per Gallon” guideline appropriate?
Unless you use levels so you are doubling or adding to the surface area of your tank, the amount of Gallons is not truly relational to the surface area. You could have a 50 Gallon tank but the surface area is actually very small because it is a fish tank, with a tall vertical height for the benefit of fish, which need it. Perhaps what would be more fitting is to say ‘per square foot’ or ‘per square metre’ so that we have an idea of how much actual surface area you are talking about. Then if people have levels, they can measure the square foot or metre dimensions and get an estimate as to how many hermit crabs they can keep in that tank. To be honest, the best way to work out how many hermit crabs you can fit within an area is to put all the things you need within a tank, such as food and water dishes, hiding spots (caves, coconut huts, etc), greenery, wood items, etc until you have created a comfortable habitat for your hermit crabs. Then calculate how many hermit crabs can comfortably
