This article is about Water Filtration Machine in Subnautica. For the related article on the Below Zero Wiki, see Water Filtration Machine.

The Water Filtration Machine is a Habitat Compartment that gives the player a stable and consistent supply of water and salt. It can be constructed with the Habitat Builder and placed on a wall in a Multipurpose Room.


The Water Filtration Machine utilizes Energy from the Seabase to desalinate the ocean water, producing Salt and Large Filtered Water. It takes about 15 minutes and 40 seconds to produce one Large Filtered Water which will give you 50 water level and takes 7 minutes and 40 seconds to produce one Salt. The Water Filtration Machine uses 0.85 points of Energy per second, or 51 Energy per minute (taken two or three at a time), and thus can be powered nonstop with four Solar Panels above 100m depth or almost nonstop with one Bioreactor.

When added to a base, the Water Filtration Machine will lower the Hull Integrity by 1.0 units. 

The Water Filtration Machine can store two pieces of salt and two bottles of water. This means that if the Player takes out the water but leaves the salt inside, it will continue to generate water but not produce any more salt. It will stop working once its inventory is filled: in this state it ceases to draw power from the base. 

The Water Filtration Machine can be built above water but will produce no salt and water at 1/8th of the speed below water

If powering the Water Filtration Machine with a consumable energy source such as the Bioreactor, note that each Large Filtered Water takes 799 energy to produce. This means that the Water Filtration Machine will consume 1,598 power when left unattended.


TitaniumTitaniumTitaniumCopper WireAerogelArrow-right (1)Habitat BuilderArrow-right (1)Water Filtration Machine

Data Bank Entry


The filtration system draws water unfit for human consumption from an external source, atomically splits it into its constituent parts, and outputs consumable liquid water and salts, while disposing of any harmful by-product. It can be built in any compatible habitat module, but has substantial power requirements.

'The Alterra Water Filtration System: Any liquid into pure, refreshing, pH-balanced water? Yes sir, ANY liquid!'



  • When the Water Filtration Machine was originally added it was extremely cheap to build, requiring only 2 Titanium and nothing else.


This section contains bugs related to Water Filtration Machine. Make sure to only post reproducible bugs, and use appropriate system template ( XboxLogo, PlaystationLogo, WindowsLogo / AppleLogo ) depending on which platform(s) the bug has been encountered on.

  • WindowsLogoXboxLogo A Water Filtration Machine will block the construction of base modules on the two panels adjacent to it, but not its own panel if the new module generates a corridor. If the player constructs such a module with the machine still in place, the Water Filtration Machine will be deleted and the resources used to make it will be lost.
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