
If you want to keep animals as pets or if you want to create a small environment for plants, you’ll need the proper space. Many people simply buy a container and give it little to no thought – which is a surefire way to ruin the habitat inside. What if you buy a container with thin glass when you need thick glass? What if you buy a plastic container that leaches? What if you buy a tank with toxic silicone? You have to do ample research before choosing the right tank or container. Moreover, you’ll have to decide on what kind of habitat you want to cultivate, whether it has plants, land animals, water animals, amphibians, or anything in between. Below, you can learn about the difference between a terrarium and aquarium and decide what’s best for your pet.
Definitions
Both terrariums and aquariums are versions of vivariums. The word vivarium comes from the Latin word vivere, meaning to live, and the suffix –arium, meaning associated with something. Essentially, it means a place of living. We use the terms now to explain small habitats that are kept in homes, offices, classrooms, science labs, zoos, and more.
A terrarium means a place for land, as terra means earth, or land-related. Aquariums, therefore, are places for water, as aqua is aquatic, or water-related.
You can house different kinds of animals and plants in terrariums and aquariums. Let’s examine the general living conditions of each.
Water

Aquariums are totally filled with water. You generally keep fish, crustaceans, mollusks, and the like in aquariums. The aquarium must be very sturdy to house what goes inside of it – water, rocks, substrate, plants, and more. You’ll need to ensure that your aquarium has thick glass and is not susceptible to leaks. Silicone may be used as a sealant.
Depending on the kind of fish you have, you may need a water heater, or you might need to alter the water’s salinity. Some fish can only live in specific conditions, and if the water is too warm or too cold, they won’t survive. It is also extremely important that you research what kind of fish can cohabitate; it would be an unfortunate circumstance if you mistakenly put together fish that live in different habitats or water types.
In terrariums, there may be a bowl of water or something similar so the animal can stay hydrated. However, it will be very small and not take up the majority of the tank.
If you are interested in having both land and water in your tank, you could consider a paludarium or a riparium. A paludarium contains enough water and land to house animals like tree frogs and salamanders; a riparium is meant to emulate a shore line or riverbank, so there is more water than land.
Multiple Creatures
Aquariums can house a fair amount of different fish depending on the size of the tank, as well as other creatures like pleckos and crabs. You can have multiple creatures in a terrarium as well, but you’ll need to be careful about the types. For example, you generally shouldn’t house two snakes together, as they may compete for warm areas, infect one another with illness, compete over food, and more.
You can usually house animals and plants together, though. You’ll just have to research compatibility.
Humidity
Aquariums do not have any need for humidity differences because they’re filled with water. Terrariums, though, may need humidity control systems or heat lamps to ensure that your pet is in a healthy environment for it.
Carbon Dioxide Injections
In the event your aquarium is low on carbon dioxide (CO2), you’ll need to inject some into it. You will not need to do this for a terrarium.
Enclosures and Lids
Aquariums tend to have lids or covers that can be lifted or pulled over for simple access for feeding, vacuuming, sweeping, cleaning, adding materials, or extracting pets. The lids often have thermometers or heaters attached to them, as well.
Terrariums should not be fully enclosed. This is why the lids are usually mesh or wire, which allows ample oxygen to flow in and will allow for quick handling of the pet if you have to remove it. Semi-open containers also won’t overheat or trap heat.
Glass

Because the aquarium has to hold so much more weight, it needs to have a very thick glass as the housing. There is a lot of pressure being exerted by a few gallons of water and by any rocks or substrate pressing against the sides, so it has to be able to handle the stress. Thick glass is also less susceptible to cracking or breaking when there are temperature changes inside and outside of the enclosure.
You can use an aquarium as a terrarium (although it is generally a better idea to get a specific terrarium for a land animal), but not the other way around.
Size
Aquariums are usually larger than terrariums because they can hold more animals at once and need to withstand water pressure. However, because of the thickness of the glass and the size of them, they’re essentially immobile once you place them in a location. To efficiently move an aquarium, you’ll need to drain a fair amount of water (you may even need to remove your fish if you drain too low) so it’s lighter. Once you transport the aquarium, you’ll have to take care to slowly add water so the temperature does not drastically change.
A terrarium, on the other hand, usually features an animal that can be removed or handled quite easily, so you can simply take your pet out, move the habitat, put it back in, and return to normal.
Need to Learn More about the Difference between a Terrarium and Aquarium?
If you’re trying to decide whether to purchase an aquarium or a terrarium, Allan’s Pet Center can help. We’ll inquire about what pet you want or have and what might be the best option for you. Don’t forget to browse our exotic pets and see if you want to give a home to a fascinating new creature, too! Contact us for more details or if you want to know any other difference between a terrarium and aquarium.