How to keep lobsters in a tank

Lobsters are marine crustaceans that thrive in cold saltwater. Their meat is a delicacy. Although most people like to buy fully cooked lobsters at restaurants, others prefer to cook lobsters at home after raising them in a tank. While it is possible to keep lobsters in a tank, there are many rules to follow to keep them alive and healthy.

Set up the tank according to the manufacturer's instructions. Paying close attention to setting up the tank will ensure a healthy environment for your lobsters for years to come. In general, you will need a pump to circulate the water, a refrigeration unit to keep the water at 4.44 to 7.22 degrees Celsius (40 to 45 degrees Fahrenheit), a filter to remove insoluble matter from the tank through the use of carbon bags and a bio wheel to remove ammonia and nitrate, harmful substances that can kill lobsters.

Prepare saltwater, using 30 to 35 g (1 to 1.2 oz) of commercial marine salt mix per litre (or quart) of fresh tap water, in a separate, clean container. Add a layer of sand substrate to the bottom of the tank, use the prepared saltwater to fill the tank until it reaches 5 cm (2 inches) from the top and add live rock to begin building an ecosystem. After operating the tank for several days to a week, use pH, nitrate and ammonia test strips to test the levels in your tank. When the tank reaches the proper pH level of 6.5 to 8.5 and contains no measurable amounts of nitrate or ammonia, load your lobsters in the tank at 454 g (1 pound) of lobster to 9 litres (2 gallons) of saltwater.

Inspect new lobsters before introducing them to the tank. Lobsters should have hard shells, be free from cracks and their antennae should be long with no signs of injury. Return weak or damaged lobsters to the shop. Do not put them in the tank.

Dip new lobsters in a separate container of saltwater taken from the tank and agitate, or purge, them before adding them to the tank. Purging, which should last a few seconds to 1 minute, expels waste and undigested food from the lobster's internal system and removes debris from the animal's body, keeping your tank clean and healthy.

Balance the amount of bacteria in the tank by keeping the load levels consistent. An established tank creates living bacteria in the biological filter of the tank that break down all the pollutants thrown out by the lobsters, thereby keeping the tank in balance. Since the amount of bacteria will rise and fall to accommodate the number of lobsters in the tank, if the number of lobsters suddenly doubles, the amount of waste that the current level of bacteria must process also doubles. The bacteria becomes outnumbered and everything in the tank dies. Keeping load levels consistent will prevent this. Add lobsters over the course of days, not minutes. Continue to test bacteria levels twice per week using nitrate and ammonia test strips. If the ammonia level suddenly increases, add some artificial bacteria to eliminate the ammonia build-up.

Check for foam daily. The presence of foam indicates a dead or dying lobster in the tank. Remove any wounded or dead lobsters as well as any missing claws, legs or other body parts from the tank. Allowing dead organisms to remain in the tank will poison the entire tank.

Do not feed the lobsters. In cold water, lobsters can live for months without food. Feeding them pollutes the tank, which could kill them. If you intend to keep your lobsters for longer than a few months, you may use commercial feed sparingly to avoid contaminating the tank.

Clean the tank weekly to ensure that the water does not turn green, yellow-brown or begin to smell bad. Use a vinegar/water solution, consisting of 3 tablespoons of vinegar to a pint of water, with a clean rag on the outside of the tank. Do not use soaps, sprays or any other chemical cleaners on any part of the tank. Clean the inside of the tank with an acrylic cleaning pad recommended by the manufacturer or use a non-abrasive, foam aquarium pad on a handle. Although you do not need to change the water, you must replace any water lost through purging or evaporation.

Replace the carbon bag located inside the filter canister every two weeks if you choose to use one bag at a time. Replace just one bag every four weeks if you choose to use two bags at a time. Whenever you change the carbon bag, check that the bio wheel is turning, the air pump is functioning and that the water level in the container remains about 5 cm (2 inches) deep.