Oxygen Not Included Wiki

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Oxygen Not Included Wiki
This article has not been revised for the current version (U39-490405). It was last updated for LU-356355. It may contain inaccuracies.
This article has not been revised for the current version (U39-490405). It was last updated for LU-356355. It may contain inaccuracies.

Water Sieve uses Filtration Medium to purify Polluted Water. It needs to be supplied a Filtration Medium and receive Polluted Water in a Liquid Pipe on its Input port to function. It will output Water to the Liquid Pipe on its output slot. It will drop Polluted Dirt on the floor when its internal storage is full.

The Water Sieve does not change the water temperature.


The Water Sieve is a very helpful tool as Water is a heavily important resource. It lets a colony operate structures like the Carbon Skimmer or the Lavatory without losing clean water in the process by instead consuming Filtration Medium which is a much less important resource and easier to obtain. Once you begin to explore other biomes like the Swamp Biome, it is needed to be able to make use of the Polluted Water found in it.


  • ONE constantly running Water Sieve can process up to 3 tonnes of water per cycle.
  • This is equal to 300 Lavatory+Sink uses OR 100 Shower uses per cycle (their peak use nature may necessitate buffers).
  • One pipeline can support 2 sieves.
  • One sieve can serve up to 5 Carbon Skimmers and
  • One sieve produces enough Polluted Dirt to keep 2 Compost piles busy.


  • If the Water Sieve is out of Filtration Medium, it will stop receiving any liquid from its Intake Pipe.
  • The Water Sieve will not be damaged by clean Water, Salt Water, or Brine, it will simply pass it along, without changing its temperature.
  • The Water Sieve will not remove any germs contained in the water, so be sure to keep waste water and your main water supply in separate systems. Once germs get into a sieve, they proliferate and any future water output is contaminated with germs.
    • So far, it does not affect gameplay unless water output is used to prepare food in Microbe Musher, used to fill the Water Cooler, Espresso Machine, Juicer, and Soda Fountain, or feeds an Electrolyzer or Algae Terrarium, both of which will aerosolize the germs, potentially contaminating any surfaces the output gasses touch.
    • With minimal germs in the water running through the sieve, while being in an oxygen or purer gassed environment (e.g. CO2, H2, Cl2), most or all germs will die off before contaminating the output products (or output products themselves may also be continuously purified). Also, Algae Distillers (with Slimelung contaminated slime) and washing hands of Slimelung (both produce PH2O) will offset (i.e. purify) food poison germs once combined into the same storage.

See Also[]

  • Gulp Fish - provide an alternative method of Polluted Water purification.