Subnautica Wiki
This article is about Alien Containment in Below Zero. Click here for information on this subject in Subnautica.
This article is about the Alien Containment. You may be looking for the Aquarium.

QuoteBar (BZ).png
TestQuoteIcon (BZ).png

An aquarium just for looks, or your own personal sushi factory. You decide.

― PDA.

QuoteBar (BZ).png

The Alien Containment is a large, cylindrical aquarium which can be filled with Fauna that has been caught or hatched by Robin Ayou. It can be built using the Habitat Builder inside a Multipurpose Room or Large Room.


In order to get inside of—or put fish into—the Alien Containment, the player must build a Hatch on the side. The player can then enter the Alien Containment and release caught fish into it. Non-edible fish can be added through the use of their respective eggs. If two or more Multipurpose Rooms are stacked on top of each other, building Alien Containments inside each room will cause the Containers to merge into a singular, larger tank. 

When built inside of a Large Room, the Alien Containment takes up two of the central floor spots, for a tank about twice the size of the one created in a Multipurpose Room. A Large Room can accommodate two of these extra-large Alien Containments. They will still stack as normal if built in stacked Large Rooms, and can be entered with a Hatch. Large Room Alien Containments have double the flora and fauna capacity of the Multipurpose Room version, and furthermore are not limited to pure vertical stacking. Stacked Large Containments can be offset by one node, allowing exotic shapes such as terraces, zigzags and arches.


If the player leaves two creatures of the same species inside the Alien Containment for long enough, they will breed and another fish of the same species will spawn inside. Once the Alien Containment reaches a population of ten fish, the reproductive process will stop. If more fish are added after the maximum is reached, some will die and float to the top of the container. Multiple Alien Containments stacked on top of each other will increase the amount by ten each. The population capacity of Alien Containments constructed in Large Rooms is twenty.

Eggs can be placed inside the Alien Containment. This can be done by simply by physically entering the tank via a hatch and dropping them from your inventory. Eggs will take about three to five in-game days (sometimes less) in order to hatch. When hatched, the fauna within the eggs will create smaller versions of said fauna, and will grow inside the Alien Containment. Non-edible Fauna can be bred this way to be used as fuel for the Bioreactor. Keep in mind that egg-laying fish will keep laying eggs (so long as there are two or more) and hatching them until the population cap is reached, as stated above. The process can be sped up by sleeping.

Flora can be placed inside the Alien Containment, via a Planter UI that appears when hovering above the soil. This has sixteen slots (4×4) in an Alien Containment built in a Multipurpose Room, and 32 slots (split into two 4×4 blocks) in one built in a Large Room. This can be used as an alternative to the Exterior Growbed for farming aquatic resources.

Aggressive Fauna hatched inside the Alien Containment will have a Passive attitude towards the Player when they enter the Alien Containment, and if they are released into the wild. Aggressive Fauna hatched inside the Alien Containment will not attack other fauna inside the Alien Containment, but will attack other fauna if released into the wild, even other fish hatched inside the Alien Containment. Once released into the wild, Aggressive Fauna will also attack small player vehicles, regardless of whether the player is in them or not, although they lose interest much faster than their wild counterparts.


The blueprint for this object is acquired by scanning the Alien Containment inside the Mercury II (bow)

1x1 default bg.png
Habitat Builder Icon.png
Item Arrow.png
Glass Icon.png
Titanium Icon.png

Item Arrow.png
1x1 default bg.png
Alien Containment Icon.png

Databank Entry

Alien Containment

Despite huge, Alterra-led advancements in stellar technology, exploring new worlds still has its challenges, and alien lifeforms are one of them. That's why we built the alien containment unit. The unit is designed primarily to breed larger or more dangerous species.

Technical Provisions:
- Units must be installed in multipurpose room modules
- Units may be connected between rooms stacked in a column
- A hatch must be installed in order to access the unit
- The base of the unit is a planter, allowing sea flora to be grown from seed

Breeding Tips:
- Provided sufficient time and living space, organisms of the same species should mate and reproduce
- Eggs inside the unit will hatch over time
- Organisms raised from birth in captivity often exhibit unusually passive behavior

- Environmental controls may fail if the unit is overpopulated
- Infections may be transmitted faster between specimens in artificial environments
- Never tap the glass: you don't know what will tap back, or how hard

Source: Unlock the Alien Containment