Things You'll Need
- 1-gallon bucket made from food-safe plastic
- Airline tubing
- Airline valve
- Small aquarium heater
- Fish net
Instructions
Test your aquarium water for nitrates. Nitrates are a natural part of water chemistry in both freshwater and saltwater aquariums. That nitrates are being generated is a sign the tank is healthy; however, if nitrates are not exported in some way, they can poison fish and crabs. Crabs are more sensitive to nitrates than fish, and elevated nitrate levels will kill them. Ideally, you want you water to have an undetectable level of nitrates (reading 0 on the test). You can accomplish this by introducing plants (for freshwater), macroalgae (for saltwater) and by frequent water changes (at least 10% total water volume per week).
Test your aquarium water for copper. Copper is lethal to crustaceans, including crabs. Even a small amount of copper in the water system will kill the crabs when they are introduced. There are test kits for copper available at most specialty aquarium stores and online, and it is worth the money to buy a test kit to avoid killing your crabs. Tap water sometimes contains copper, and if you use tap water to make your aquarium water, crabs may not be able to survive. Instead, use filtered, distilled, or reverse osmosis water.
Put crabs and the water they came in into a bucket about a gallon in volume. When you purchase crabs from the store, they will come in a small amount of water. Add the crabs and the water to the bucket. Make sure the water is deep enough so that the crabs are completely submerged.
Set up a drip line from the aquarium to the bucket. A drip line is easy to create with a standard airline tube and a plastic airline valve. Place one end of the airline into the aquarium and place the other end into the bucket, and insert the valve into this end. Start a siphon with the valve open then close down the valve until you have about 4 drips per second.
If it is cold in the room, add a heater to the bucket or a heating pad under the bucket. You want the water to stay around 80 degrees Fahrenheit for saltwater and around 70 degrees for tropical freshwater. Remember that the crabs are already stressed and you don't want to add temperature fluctuations as a new stress factor.
Let the water drip into the bucket until the bucket is full. Typically the crabs will be well acclimated at this point, but you can empty half the bucket and continue the dripping process to be absolutely certain.
Using a net, add the crabs to the aquarium. Do not add the water from the bucket. Generally speaking, you want to avoid adding water from the fish store into your aquarium, just in case it contains diseases or parasites.
Dim the aquarium lights. When first introduced to their new environment, the crabs will feel threatened and look for shelter. Unless you have lots of potential hiding places, dimming the lights for the first day will help reduce the stress on your new crabs.