If you’ve ever found yourself stuck mid-base build, short on chlorine for advanced life support upgrades or explosive crafting, you know how frustrating it is to run out of this high-demand resource halfway through a project. I’ve spent dozens of hours testing different resource gathering methods across multiple playthroughs, and I’ve broken down exactly how to make chlorine in No Man’s Sky without wasting hours grinding on toxic planets. Chlorine isn’t just for basic survival either – it’s a key component for trading, crafting high-tier tech, and even powering some late-game base utilities. This guide covers every reliable method, from early-game gathering to late-game automated farming, so you can pick the one that fits your current progression level.
How to Make Chlorine in No Man’s Sky via Refining (Most Accessible Method)
If you’re still in the early hours of your playthrough, refining is the fastest way to get chlorine without risking exposure to toxic planet hazards. You won’t need any special gear beyond what you unlock during the initial tutorial missions to pull this off. The only required tool is A Portable Refiner, which you get as part of the first questline to fix your crashed starship.
You have two refining recipes to choose from, depending on how much extra oxygen you have stored. The basic recipe turns 2 units of salt into 1 unit of chlorine, but this is very inefficient if you have a decent stock of oxygen. The 1 Salt + 2 Oxygen refining recipe is 5x more efficient than basic salt refining, turning just 1 salt and 2 oxygen into 5 full units of chlorine. You can get salt easily by scanning shorelines on any ocean or frozen planet with your analysis visor, and you can collect oxygen from local plant life while you mine, so you won’t have to make extra trips to restock.
That means you can pull up to a random ocean planet, spend 10 minutes mining salt, and walk away with enough material to make thousands of chlorine units in less than 30 minutes of refining time. You don’t even have to stay on the planet while refining runs – you can hop in your ship and do other tasks while your refiner processes the materials in the background, as long as you don’t travel to a different star system.
Fast Chlorine Farming for Mid-Game Players
Once you unlock base building and gas extraction tech, you can set up a fully automated chlorine farm that produces resources even when you’re off exploring other systems. This method is perfect if you need massive amounts of chlorine for trade, large base builds, or freighter upgrades. You won’t have to do any manual mining or refining once the setup is complete.
To build a basic automated chlorine farm, you’ll need the following items:
- 1x Medium or Large Refiner for bulk processing of extra raw materials
- 2-3 Gas Extractors placed directly on active chlorine vents
- 4-5 Supply Depots to store harvested chlorine while you’re away
- 1x Solar Panel and Battery array to power the setup 24/7 regardless of weather
You can find chlorine vents by switching to your analysis visor and looking for the green gas icon marked “chlorine source”. Most toxic planets have dozens of these vents clustered together, so you can set up multiple extractors in the same spot to maximize output. If you have the Atmospheric Harvester upgrade for your exosuit, you can also passively collect extra chlorine just by walking around the toxic planet while you build, no mining required.
Just make sure you bring a few stacks of sodium with you to recharge your hazard protection while you build the outpost. Toxic planets will drain your shields fast if you don’t stay on top of recharges, and you don’t want to die halfway through building your farm and lose all your construction materials. I’ve had a setup like this running on a toxic planet in my Eissentam save for months, and I’ve never run out of chlorine for trade or crafting since I set it up.
Profiting From Excess Chlorine: Bonus Tips
Once you have a steady supply of chlorine coming in, you’ll probably end up with far more than you need for your own crafting and upgrades. Luckily, Chlorine is one of the most valuable mid-game trade resources – a full stack of 9999 chlorine sells for over 2 million units at any space station or trade terminal. That’s a great way to make fast units to buy new ships, upgrade your exosuit, or expand your freighter fleet.
You can also use excess chlorine to craft other high-value resources instead of selling it directly. For example, combining chlorine with condensed carbon makes advanced explosive charges that clear terrain 3x faster than your basic terrain manipulator, which is perfect for large base builds or excavating buried treasure. Chlorine is also a key component for advanced life support modules that let you stay on hazardous planets for 3x longer without recharging your hazard protection.
I usually keep 2 stacks of chlorine in my exosuit inventory at all times – one for crafting and upgrades, and one to sell if I come across a rare ship I want to buy while I’m exploring. If you have a frigate fleet, sending your mining frigates on chlorine mining expeditions will give you a steady supply of extra chlorine without any extra work on your part, as long as you have a few high-level mining frigates in your fleet.
Common Mistakes to Avoid When Making Chlorine
A lot of new players waste hours grinding chlorine the wrong way, so I’ve put together a list of the most common mistakes to help you save time. First, don’t waste time mining chlorine directly from toxic planet surfaces with your terrain manipulator. This method is 10x slower than refining salt or using automated extractors, and you’ll burn through all your sodium recharging hazard protection before you get enough chlorine to be useful.
Second, don’t use the basic 2 salt = 1 chlorine recipe if you have extra oxygen lying around. The boosted recipe gives you 5x more output for the same amount of salt, so you’ll get way more chlorine for the same amount of mining work. It’s easy to forget this recipe exists if you don’t check your refiner menu regularly, so make a note of it next time you fire up your refiner.
Third, Don’t forget to add supply depots to your automated extractor setups. If you don’t have external storage connected to your extractors, they will stop producing once their tiny internal storage is full, so you’ll waste a lot of potential output. I made this mistake with my first chlorine farm, and I came back after a week of exploring to find the extractors had stopped running after just a few hours. Connecting even 2 supply depots to each extractor gives you enough storage for days of passive production.
Finally, don’t sell all your chlorine even if you have a massive stockpile. Keep at least 500 units in your inventory at all times, because you’ll need it for a lot of main story missions and late-game tech upgrades, like the hyperdrive range upgrades for your freighter. I made this mistake early on, sold all my chlorine for units to buy a new fighter ship, then got stuck on a main story mission that required 300 chlorine to build a special component, and had to spend 2 hours grinding to get more.
At the end of the day, figuring out how to make chlorine in No Man’s Sky doesn’t have to be a tedious grind, no matter what stage of the game you’re in. If you’re just starting out, stick to refining salt with oxygen to get all the chlorine you need quickly. Once you’ve got a bit more gear, setting up an automated farming outpost on a toxic planet will let you stockpile hundreds of thousands of units worth of chlorine without lifting a finger. Play around with the different methods to see what works best for your playstyle, and don’t forget to keep a small stockpile in your inventory for unexpected crafting needs.
