Crabs need a small area above the water line as they are semi-aquatic creatures. Hence, many aquarists keep a huge rock which rises above the water line. Make sure that the rock is not near the glass walls of the aquarium as the crabs can escape.
Decorations and connections to the aquarium equipment such as air tubes and wires should be carefully arrange so that the crabs do not escape from the aquarium.
Crabs eat uneaten food and keep the bottom clean. In addition, some crabs eat snails and keep them under control. Crabs also preen live plants in their search for food.
Flake food which sinks to the bottom are ideal for crabs. Crabs also eat brine shrimp and worms.
Like all invertebrates, they are vulnerable to fish medication. Therefore, remove your crabs from the aquarium before adding the medication