Slightly brackish water should be made using special aquarium salt, rock salt, or another noniodized salt. [2] X Research source Do not use regular table salt, as it contains iodine, which the crabs don’t like. Mix the brackish water to a salinity of about 30 parts per thousand. Follow the salt’s directions to obtain the desired concentration.
Never use live plants; the crabs will damage them and they might act as vectors for various bugs and mites.
Feed fiddlers sparingly so as not to pollute their water. If you see food has been eaten, add more to the crabitat; if you see food uneaten in the tank after several hours have elapsed, wait before feeding again.
The only time for real worry is when a crab is being harassed right after it has molted. At this time, the crab will be fragile for several days. Remove the aggressor if you notice repeated violence against the freshly-molted crab. [9] X Research source Crabs have amazing healing properties. Missing claws and legs will eventually regenerate after several successive moltings.
Decorate your “crabitat” with plastic plants, driftwood, and climbing accessories which the crabs can clamber over and hide beneath.
Check the temperature and humidity levels each day. Substrate should be at least two to three inches deep and may be of gravel or fine reptile bark bedding, which better maintains the appropriate humidity levels.
Hermies may croak or chirp when squabbling with another crab. The sound is natural, so don’t worry.
A shell’s opening should be about 1/8 inch larger around than the width of the crab’s large claw. Boil all shells before introducing them to the crabitat. This will wash off any lingering odor which the crab finds unpleasant.
In order to prevent the crabs from burying their food in the substrate, offer fresh food in a separate container outside of tank. When you want to give the crabs something fresh, remove them to a separate space – another tank, or a small cardboard box with a towel on the bottom – and let them eat. This will ensure their tank remains clean. [17] X Research source Crabs can go many days without eating. While molting, crabs may not eat for a month. [18] X Research source If you see your molting crab not eating, don’t worry.
Next, sterilize all the tank decor and extra shells by boiling them for about five minutes in water. If you have wood or rocks, sterilize them by putting them in the microwave for about 2 minutes. Be sure to watch the wood carefully to ensure it doesn’t catch fire. Install new substrate, replace the crab toys, and put the crabs back in the tank. Instead of throwing out and buying new substrate, you could remove all substrate and bake it in a baking sheet at 300 °F (149 °C) for 30 minutes. Prevent future mite outbreaks by removing uneaten food scraps and don’t introduce live plants into the crabitat, since they may act as a vector for mites and bugs to enter. Don’t buy crabs from beachside stands or mall kiosks. Crabs at these places are likely not being cared for properly, and are often left exposed to direct sunlight, heat, and cold, and live in crowded conditions where mites and bugs thrive. [20] X Research source
Besides driftwood, give your crabs plastic plants, castles, and other climbable aquarium objects to explore.
Ensure your crabs get enough calcium. Cuttlefish bone can be nibbled on for extra calcium, and commercially available calcium supplements can be sprinkled on fresh foods before you serve them to your crabs. [25] X Research source
