Polluted Water is an obnoxious substance in Oxygen Not Included, it’s a breeding ground for bacteria, it’ll make your Duplicants sick, it pollutes clean water, and over time it will spit out Polluted Oxygen. It’s in your best interest to managed the Polluted Water in your base before it gets out of hand and causes you headaches.
Some methods for dealing with Polluted Water are better than others and like anything in Oxygen Not Included you should find ways to turn this nuisance into a benefit for your community. If you find your Duplicants knee-deep in Polluted Water here are some ways to get rid of it.
10 Use It As Coolant
In spite of the toxic side effects and stress it can cause your duplicants Polluted Water is actually a very helpful tool when used as a coolant. It reaches much colder temperatures than standard water and it frees up your pure water for better uses like irrigation or drinking.
It takes some brainpower to figure out a way to use it as a coolant while restricting its ability to infest your water systems and the air, but if you can work it out it’s a great way to take a nuisance and use it to your benefit.
9 Irrigate Plants
Interestingly there are some plants that actually require the presence of Polluted Water to grow. Pincha Pepper, Thimble Reed, and Arbor Tree all need Polluted Water. Pincha Peppers are used in high-quality food recipes, Thimble Reeds are used to produced clothing like Atmo Suits, and Arbor Trees are a good source of fuel for your machines.
So if you have Algae Distillers, Lavatories or Showers that are leaking, or a Duplicant who is using one of your pure water reservoirs as a toilet, it can be diverted to growing useful plants to improve your Duplicant’s lives.
8 Turn Into Fertilizer
Speaking of plants, that polluted water can also be converted into Fertilizer using a Fertilizer Synthesizer. It requires combining Polluted Water, Dirt and Phosphorite that will produce Fertilizer and a little bit of natural gas.
Fertilizer can be used on almost any plant to double its growth rate for one cycle. It’s a great way to cut down on plants with lengthy maturation times like Nosh Sprout. If you don’t need the Polluted Water for cooling anything down or feeding plants this is a great use.
7 Purify Into Clean Water
If you don’t need it for the above purposes then the next best thing you can do is purify Polluted Water into clean water. It’s not as efficient as the above methods, but if your Duplicants need the drinking water or you accidentally contaminated a clean reservoir then this is what you should do with it.
To purify Polluted Water pump it via a Liquid Pump into a Water Sieve or put Gulp Fishes in the reservoir. This doesn’t remove any of the germs, so you’ll need a second step to make it safe to drink like adding a bit of chlorine, but if you just don’t need the water for drinking or bathing then you’re probably good to go.
6 Bottle It
If the Polluted Water is in a weird spot, there’s not a lot of it, or you don’t have the means to purify or use it, then bottling it is a good option. Simply place a Pitcher Pump over the liquid and have your Duplicants transport the bottles by hand to a storage area.
Your Duplicants won't be infected by germs, but they may accidentally put them in your Wash Basins or Microbe Mushers so keep an eye on them while they’re transporting the bottles and make sure they don't pull it out of storage. Otherwise, it's a great way of storing the liquid that has zero risk of infecting other water supplies.
5 Feed To Hatches
Some players have had success producing coal by feeding Polluted Water bottles to their Hatches. To do this simply put the bottled water in the path of the Hatches and wait for them to eat one.
Granted this is by no means efficient and certainly isn’t a guaranteed means of production. But if you’ve got a large stockpile of bottled Polluted Water and don’t know what to do with it, just chuck them near your Hatches and let them deal with it. Plus the extra coal now and then is always nice and can save you food.
4 Boil Into Steam
The last beneficial use of Polluted Water is to turn it into steam and use it in Steam Turbines to power your base or use it as fuel in Steam Engines. Keep in mind this is incredibly inefficient as Polluted Water takes 121.35 degrees to turn into steam whereas clean water only requires 101.35.
There’s also the issue that Polluted Water produces blocks of dirt when it evaporates which can pose problems for your system and require Duplicants to constantly clean it up. It can be done, it’s just not very efficient and can get annoying every now and then.
3 Isolate It
If you absolutely don’t have a use for Polluted Water and don’t want to mess with it then the simplest thing you can do is isolate it. Whether you dump it into a naturally occurring cavern or a carved out reservoir just stick a pump in the water and use piping to pump it wherever you want.
This is handy if you lack the resources to purify it or if you want to hang onto it for plant irrigation and just don’t have your garden set up yet. It’s an easy way to get it out of your base while still holding onto it for later use.
2 Freeze It
If you’re still worried about the Polluted Water contaminating your systems then you can store it safely by freezing it. You can use an Ice Maker to freeze your reservoir or you can simply dump the infected supply into a Frozen Biome and let the cool environment do the work for you.
This is by far the least efficient storing method and if you use the Ice Maker it can be a waste of resources. Unless you have a plan for using frozen Polluted Water, just store it in its liquid state.
1 Dump It
The final option and least recommended for dealing with Polluted Water is to dump it into space. Routing your Polluted Water through pipes to the edges of the asteroid and letting the vacuum spew it into the void is certainly an option for getting rid of it.
But honestly, you are removing a potential resource from the game that could benefit your Duplicants lives. Unless your Duplicants are drowning in Polluted Water and it's a matter of life and death you should be using or storing it.