Lobsters don't wind up in aquariums like various crab and shrimp species do, for a number of reasons. Many types of lobsters make poor aquarium pets, thanks to their special care requirements. But a few species can work in aquariums as long as they have appropriate roommate selection and aquarium accommodations.
Picking Your Lobster
Dozens of species of lobsters exist, but few are well-suited to life in the home aquarium. For example, most lobsters come from temperate regions and need colder water, typically somewhat cooler than room temperature. This requires an expensive chiller unit, which typically start at several hundred dollars. Some species of rock and spiny lobster come from the tropics and can work in a home aquarium. However, these species require their own tanks since they will eat just about anything else. Of all of the lobsters, the reef lobsters, particularly the smaller species, can live in a reef aquarium with few concessions. To avoid surprises, always research the exact species you want to keep before you buy it.
Lobster Aquarium Size and Setup
As a general guideline, use the lobster's length to determine the minimal aquarium size. Ideally, you select an aquarium based on the length of the lobster. The aquarium's footprint should measure 2.5 lobster lengths by 2 lobster lengths. For spiny and rock lobsters, this translates to an aquarium of at least 75 to 120 gallons for most species. However, smaller reef lobsters can thrive in an aquarium as small as 5.5 gallons. When setting up the aquarium, make sure it has plenty of hiding places so the lobster feels secure.
Again, different types of lobsters have different requirements. Spiny and rock lobsters usually need display aquariums of their own. They will eat pretty much anything else you add to their aquarium. However, reef lobsters have less complications. They may pick on some invertebrates like smaller crustaceans but generally leave sessile invertebrates like corals alone. This makes them definite maybes for reef aquariums. However, they may eat fish smaller than themselves if they can catch the fish sleeping. Conversely, do not keep them with large, predatory fish like lionfish, which can eat reef lobsters.
Diet varies by the type of lobster. Spiny and rock lobsters need a diverse diet, including various types of seafood. Rotate through meaty foods such as crab, fish and mussels. They also need some veggie foods, so feed them dried nori or algae pellets from the fish store. Reef lobsters are enthusiastic omnivores who will usually eat whatever they can scrounge from the aquarium. When you feed the other fish and invertebrates in the aquarium, make sure enough reaches the bottom to make a meal for reef lobsters.