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How to farm Acid in Once Human

Here’s how to farm Acid, and how to start your very own Acid farming operation in Once Human.

The player faces a production facility at Blackfell Refinery in Once Human
Image credit: VG247/Starry Studio

Once Human tasks you with surviving the post-apocalyptic wilderness, and to do that without becoming zombie food, you’re going to need powerful guns and lots of ammunition. That, and a nice base to return home to where all those resources you need to live produce themselves for the most part, or Deviations farm them for you.

The good news is that when it comes to Acid — a resource needed to create gunpowder and therefore, ammo — you can have your base farming this while AFK. Though, in most instances, you will need to farm this one yourself. To help you with that, here’s how to farm Acid in Once Human, and how to build your very own Acid farm at your base.


How to farm Acid in Once Human

There are a few different ways you can go about farming Acid in Once Human, and some of them are much more efficient than others.

Kill enemies at Strongholds and other Points of Interest

First things first, you can collect plenty of Acid by simply killing enemies at various Strongholds and Points of Interest around the map. Gnawers tend to always drop Acid on death, but you will find that other enemies such as Charred Maniacs will sometimes drop it, too. These enemies tend to drop between 1-4 Acid at a time.

If you plan on doing this, cook the Preserved Deviated Chops at an Electric Stove where possible. Consuming these before farming a bunch of enemies will have them drop 50% more Acid! To cook these, you'll need to unlock Dishes 3 from Tier 4 of the Logistics tab of your Memetics Menu.

Use your Access Cards and Permits

Similarly, you can farm Acid by using your Access Cards and Permits at production points around the map. If you have any Access Cards or Permits in your possession, you can visit the named location on them and use the card to produce Acid, fuel, and Stardust Source.

The player uses a Refinery Permit at the Blackfell Refinery in Once Human
Use Permits and Access Cards to get Acid and other loot from production facilities around the map. | Image credit: VG247/Starry Studio

While your items are produced, though, you will have to fend off several waves of enemies. The good news is that these enemies tend to drop more Acid, so that’s great!

Refine Starchrom, and kill the enemy waves

Similarly, if you have any Eclipse Cortex’s or other items that can be refined into Starchrom, you can do that using a Stardust Resonant Filter at your base. Once you begin production, multiple waves of enemies will descend upon your base who you can quickly kill and collect Acid from while you wait for your Starchrom to be ready.

This is a more unreliable way of farming Acid given that it relies on you refining Starchrom, but bear it in mind when next refining the stuff!

Use Water Filters to farm Acid while AFK

This next method of farming Acid isn’t the best or fastest way to get your hands on the stuff if you’re in urgent need of it in Once Human. That said, if you want your base to passively farm Acid while you are AFK or offline, you can.

To do this, you need to have access to power facilities, such as Solar Generators. These can be unlocked from Tier 3 of the Logistics tab in your Memetics menu. Secondly, you will need access to Water Pumps (also from Tier 3 of the Logistics tab), Brewing Barrels (Tier 4 of the Logistics tab) and an Osmosis Water Purifier (Tier 5 of the Logistics tab).

Once you have the formulas for everything you need unlocked, and the resources to build them, you first need to place your base in a polluted area of the map that is nearby water; our Water Pump itself will need to be in the water, while our base remains on land. It’s very important that the area is polluted, or else your Water Pump will simply produce dirty water, rather than producing both dirty water and Acid.

The player faces a Water Pump at the back of their base in Once Human
Set up your own Acid farm for when you are AFK. | Image credit: VG247/Starry Studio

Once you’ve found a place to build that you’re happy with, here’s what you need to do next. The below method was put together thanks to YouTuber, MM22.

  • Build your Solar Panels (or other Power Generator)
  • Build your Water Pump in water
  • Build your Osmosis Water Purifier and Brewing Barrels together in your base
  • Interact with the Solar Panels and press ‘X’ to connect a wire - connect wires to both the Water Purifier and Water Pump, using Circuit Modules to keep things tidy
  • Interact with the Water Pump and press ‘V’ to connect a pipe - connect the pipe to the Water Purifier
  • Interact with the Osmosis Water Purifier and connect a pipe again - this time, connect the pipes to the Brewing Barrels

Once that is all set-up and everything is going where it needs to be, dirty water will be sent from your Water Pump to your Osmosis Water Purifier, where it will be turned into Pure Water and Impure Acid.

If you then pop your Purified Water and Impure Acid into a Brewing Barrel, ensuring that Impure Acid is placed in the Raw Materials section, it will slowly be turned into fully-functioning, usable Acid over time. It’s a fair bit of work for little return, but considering you need endless amounts of ammunition, it’s good to have something at your base that is constantly producing the Acid needed for gunpowder, even if it is a bit slow.

What is Acid used for in Once Human?

There are a lot of different resources you need in huge amounts in Once Human, but ammo is one thing that you cannot afford to skimp out on. And to craft ammo, you’ll need plenty of gunpowder, which is crafted using Acid.

Acid is also used as a crafting component for multiple consumables, such as Utter Delight, and is also needed to make Storage Batteries. You'll also need it for healing items, and for crafting Tungsten Ingots or Aluminum Ingots.


For more on Once Human, take a look at our Once Human codes for some freebies, how to complete the Lost in Madness quest for some good loot, and where to get Starchrom.

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