Water

Water is one of the most important resources in the game. It is used heavily in food production and oxygen generation, and Duplicants do not need to drink it directly to survive despite the in-game description. Because it appears in many liquid systems and processes, Water remains relevant throughout most stages of a colony.

In its normal liquid form, Water is a basic ingredient for several recipes in the Microbe Musher. It is used to make Mush Bar from Dirt, Liceloaf from Meal Lice, and Tofu from Nosh Beans. These recipes make Water a direct part of early food production, especially when a colony is short on better ingredients. Water is also part of many other industrial and environmental loops, since it can be heated, cooled, piped, stored, and transformed like other liquids.

Water can be produced naturally when Steam cools and condenses. Steam itself is created by boiling Water, Salt Water, Brine, or Polluted Water in a hot environment such as a Volcanic Biome or the Space Biome. Polluted Water produces Dirt when evaporated, while Salt Water and Brine produce Salt. Since Steam is one of the major ways Water appears at high temperatures, managing the transition between Water and Steam is central to several power and heat-management setups.

Practical uses and interactions include:

• Water is a key input for food production, especially in the Microbe Musher.
• Steam can be used as fuel for the Steam Engine on space missions.
• Steam of any temperature can be used in a Sauna for recreation.
• Steam hotter than 125 °C can power a Steam Turbine, but Cool Steam Vent output is too cool to use directly without additional heating.
• Steam is a useful heat transfer medium above 100 °C because it has better conductivity and heat capacity than Hydrogen.

Because Water and Steam are so closely linked, they are often used in heat-processing strategies. Polluted Water can be purified by boiling it into Steam and then condensing it again, although direct cooling is difficult and can damage pipes if handled poorly. One common method is to cool a different gas, such as Hydrogen, and use that to cool the Steam indirectly. Another approach is to drip Water onto a Liquid Tepidizer, which can generate Steam, or to pump Water onto very hot materials at the bottom of the map, including Magma, to boil it rapidly. Batteries enclosed in an insulated room can also become hot enough to help produce Steam.

Steam is also hazardous. It quickly scalds Duplicants, so Atmo Suits are recommended before entering Steam-filled areas or working around risky water-cooled machinery. For colonies that need a steady supply of Steam for power, a Steam room can be built in the Space Biome, where hot Water can be boiled by accumulated Regolith on the ceiling and then pumped out with a Steel Gas Pump for use in a Steam Engine.