Carbon Skimmer

The Carbon Skimmer is a mid-game plumbing building used to remove large amounts of Carbon Dioxide from the air by converting it into Polluted Water. It is an alternative to using Slicksters or an Algae Terrarium for CO2 management: unlike Slicksters, it does not produce Crude Oil, and unlike algae-based oxygen setups, it does not create breathable air. Instead, it returns a liquid output that can be routed into agriculture or cleaned and reused.

Because Carbon Dioxide is heavy and sinks, the Carbon Skimmer is most effective when placed near the bottom of a colony or in any low-lying area where CO2 accumulates. This makes it a good tool for keeping living spaces from becoming overwhelmed by CO2 while also lowering local air pressure. It is especially useful in bases that produce more CO2 than their plants and vents can comfortably handle.

A Carbon Skimmer outputs the same volume of liquid it takes in, which makes it well suited to a closed loop with a Water Sieve. Once the loop has an initial amount of water, it can run without a Liquid Pump, saving 240 W of power compared with pumping the liquid around manually. One Water Sieve can support up to five Carbon Skimmers in this arrangement.

• Carbon Skimmers are commonly used as part of a CO2 cleanup chain: Skimmer -> Water Sieve -> Sublimation Station -> Deodorizer. This can produce Oxygen from CO2, but it is an expensive route and requires significant power and filtration material.
• The loop can also be tied into lavatory overflow. Filtered water from a Lavatory + Water Sieve setup can be sent through a Carbon Skimmer and then into a Hydroponic Farm tile for crops such as Thimble Reed.
• This arrangement has the advantage of removing germs from lavatory water, since Water Sieves do not remove germs at all.
• The oxygen-producing chain is inefficient compared with dedicated oxygen systems, but it can help supplement bases with limited water and large CO2 reservoirs.
• A petroleum generator produces enough power to handle the skimming and conversion of its own emissions with less than half of its output.

In practice, the Carbon Skimmer is less a direct oxygen solution and more a waste-management tool. It turns an unwanted gas into a useful liquid, making it valuable in colonies that need both CO2 control and more water flowing into farms or treatment loops.