The Ultimate Acid farming guide in Once Human (1000+ per hour) - Upcomer
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The furnace UI in Once Human showing a player inventory of over 700 Acid obtained in an hour.
Screenshot by Upcomer

The Ultimate Acid farming guide in Once Human (1000+ per hour)

Before you read this, are you sure you want all that Acid? You'll get loads with these methods!

You saw them in Global chat. Those people who are always trying to buy Acid in Once Human, like there’s some sort of shortage. Meanwhile, you’re sitting with 800 plus Acid! What are these people doing?

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And then you discover Tungsten and explosives, and oh boy, where did all your Acid go? Now you’re here, and in the same boat as me. So let’s discover three methods of producing Acid in Once Human, starting with that passive income.

Ready to get loads of acid and even sell some off? Let’s go!

What you need to produce Acid in Once Human (Method 1)

As with everything in Once Human, there are some steps you’ll need to fulfill before you can start your Acid farm. And for some reason, I can’t stop thinking about Breaking Bad as I write this. Walter would be proud.

To start up your semi-passive Acid farm, you’ll need to unlock two Memetics. Firstly, the Water Pump Memetic, which you’ll find under Logistics in the third section (03).

The Memetics Screen in Once Human with the water pump highlighted by an arrow for Acid farming.
Screenshot by Upcomer

Next, you’ll need to unlock brewing barrels. You’ll find the Brewing Battles Memetic under Logistics in the fourth section (04).

The Memetics Screen in Once Human with the brewing barrels highlighted by an arrow for Acid farming.
Screenshot by Upcomer

Now you’ll also need to find a Stardust-polluted area where you can also build. There are quite a few, and they tend to change depending on the difficulty of the server you’re playing on, but here are some of the spots you’re bound to find polluted areas.

Polluted Areas in Once Human for Acid Farming

A map of all the polluted areas on the Once Human map, marked by arrows and circles.
Screenshot by Upcomer

Here are all the polluted spots that I know of in Once Human:

  • Red Sands, east of Blackfell safe zone (4687, -1429)
  • Red Sands, east of Evergreen (4632, -2490)
  • Chalk Peak, far north-west (-1200,-2350)
  • Blackheart Region, east of the Forsaken Monolith (886.-1184)
  • Red Sands, east of the Alternate Reality Institute (7257,-1187) — this area is huge!

There are yet more areas hiding around the map, but you’re sure to find a prime spot in any of these locations, so you can get your Acid farms up and running!

Building your passive Acid farm in Once Human

A full acid farming production facility with all equipment visible in Once Human.
Screenshot by Upcomer

If you’re ever unsure, consult the above image, which displays my current setup (which only produces 36 Acid per hour, I might add). One full set consists of two water pumps, one compact and one full-size water filter, a water storage tank, and a brewing barrel.

Start by placing your water pump, which is found in the build menu under Facilities > Production Processing > Gathering & Production. Increase it’s height (Alt + Mouse Wheel) as much as you can, to ensure water flows downwards from it. Place two of them, and connect them to a power source. They’ll start to produce polluted water.

The building screen in Once Human with an arrow showing the water pump location for Acid farming.
Screenshot by Upcomer

Next, build an Osmosis Water Purifier, then attach pipes (V in Build Mode) to the water pump and connect them to the water purifier.

The build menu in Once Human with an arrow showing the location of the Osmosis Water Purifier for Acid farming in Once Human.
Screenshot by Upcomer

As the polluted water gathers, it’ll automatically run down into the water purifier, where it’ll turn into Impure Acid. Sadly, Impure Acid doesn’t like to run through water pipes, so we’ll have to manually move this later. For now, let’s move on.

To produce Acid from Impure Acid, you need pure water and a brewing barrel. So let’s start by placing down a Water Storage Tank, which is in the Build menu under Facilities > Storage Facility.

The build menu in Once Human showing the location of the water storage tank with an arrow, used for farming acid in Once Human.
Screenshot by Upcomer

You’ll need to fill this tank with dirty water manually. To do this, head to any water source and hit G, and wait. You can overburden yourself and collect as much water as you can, since you’ll just teleport home from here and put everything in the storage tank.

Now build a Compact Water Filter, which is found in the Build menu under Facilities > Production Processing > Crafting. Everything we need from here on out is in this same spot in the Build menu.

The build menu in Once Human with an arrow showing the location of the Compact Water Purifier for Acid farming in Once Human.
Screenshot by Upcomer

Now connect the storage tank to the compact filter and you’ll start to produce pure water. Just make sure that everything has enough power to function. If you need additional help there, I have a guide on power generation in Once Human as well.

Finally, build your Brewing Barrel. Connect the compact purifier to the brewing barrel and pure water will flow in passively. And that’s it. Wait for some impure acid to gather, and then move it all into your brewing barrel.

This setup consumes 46W of power in total and produces 3 Acid per hour, meaning that if you max out your power generation (theoretical limit of 300), you can only produce 18 Acid per hour. That’s not much, but it does add up slowly and is mostly passive, so this Acid is almost completely free.

Furthermore, the more slots you have filled up in your brewing barrels, the faster you’ll produce acid. With all four of your slots in the brewing barrel full, you’ll be producing 12 per hour per barrel — or 108 Acid per hour! That adds up quickly.

To really get your Acid production running fast, place tons of water pumps first, until you’ve filled a storage water tank (or two) with impure acid, then get your full production setup running. This way, you’ll be able to fill all the barrels to the max right off the bat.

Finally, getting the Deviation energy generator specialization can help you set up even more of these, so look out for that as well.

How to get Acid really fast in Once Human (Method 2)

You already know that normal enemies drop Acid. But did you know that they can make you over 600 Acid per hour? Yeah, me either, until I conducted this little experiment. I’ll walk you through it.

First, I decided to try and farm Dayton Hospital, since we don’t need to use any bullets there. I gave myself 20 minutes to get as much Acid as possible by killing normal mobs with melee. I ended up getting a healthy dose of 56 Acid in that 20 minutes. Not bad, considering we can only make a max of 18 per hour with the passive method.

An arrow showing a lower amount of Acid gathered in Once Human at Dayton Hopsital.
Screenshot by Upcomer

But then there’s food that increases the amount of Acid that drops from enemies. It’s called Preserved Deviated Chops, and can be made from peppercorns, any raw meat, and salt. You can buy peppercorns (3 per day) from Lacey in the Blackwater safe zone, you get raw meat from hunting animals, and you can make salt from seawater in your stove. You’ll need Dishes III (right beside brewing barrels in the Memetics screen) to make it though.

The cooking menu in Once Human with an arrow showing the location of food that helps to speed up acid farming.
Screenshot by Upcomer

So it’s pretty easy to make, but is it worth it? I tried Dayton again with the buff active, and ended up getting 99 Acid in 20 minutes. That’s quite the increase, despite the food only stating a 50% increase. That’s easily explained though, there is some randomness at play here. We all know about RNG, right!

An arrow in the inventory screen in Once Human showing a moderate haul of Acid while farming.
Screenshot by Upcomer

I decided to try a spot where I know mobs drop more Acid. The Blackfell Fallen zone. It’s super easy to get to, it’s right next to the safe zone there. Again, I went in for 20 minutes without the buff. This time, I used a sniper rifle to take out enemies from afar. I ended up using 185 Steel Bullets (cheap to make) and scored 164 Acid.

The inventory screen in Once Human showing a large haul of acid while farming.
Screenshot by Upcomer

I tried again with the buff active, and made 220 Acid in just 20 minutes! And this time, I only used 159 rounds. The sniper rifle (tier V) takes two Tungsten ore to repair, leaving me with a profit of 218 Acid per hour. Before you ask, yes, I cleared out my inventory before each run.

The inventory screen with an arrow showing a huge haul of Acid while farming in Once Human.
Screenshot by Upcomer

The buff lasts for 30 minutes, and you can make three dishes per day (more if you buy the seeds and grow your own). This gives us 90 minutes of farming per day, which could, theoretically, make us 990 Acid.

I don’t know about you, but that’s not a bad haul. That’s without collecting all the resources in the Blackfell Fallen Zone, which could add even more Acid to the payout.

The final (biggest haul per hour) to get Acid in Once Human (Method 3)

Have you heard of refinery runs? Not only do you get to farm acid, you’ll also get Barreled premium fuel and Stardust Source out of the deal. Using this method, it’s possible to obtain well over 1,000 Acid and Stardust Source per hour!

A player inventory after farming the refinery in Once Human for Acid and Stardust Source.
Screenshot by Upcomer

Just make sure to bring along some of those deviated chops. Here’s how to complete the refinery purification.

How to complete a Refinery Purification for Acid and Stardust Source in Once Human

The first thing you’ll need are either Blackfell Extraction Permits or Blackfell Refinery Permits (the latter are better). Be warned, however, the tier IV defense missions can be a challenge, so don’t attempt one if you don’t have a strong build or some backup.

Next, head over to a Refinery – the one I tested is located in Red Sands at the Blackfell Oil Refinery (5269,-1473). Walk up to the Production Facilities, select a card, and off you go.

The location of a refinery which players can use to farm acid in Once Human marked on a map with a circle and arrow.
Screenshot by Upcomer

If you’re running it with a strong team, you can simply fast forward the first stage and fight the attacking enemies immediately. If you’re solo, or prefer not to take chances, enter build mode and block up all the entrances before you start the defense.

Enemies will attack in waves, and you simply have to hold them off. The whole thing only takes five minutes, and you can restart it in another two minutes. Remember to claim your rewards from the production facilities after a successful defense, and enjoy your mountains of Acid and Stardust Source!

If you need fuel (another important component), check out my guide to fuel production in Once Human.

Author
Image of Kyle Ferreira
Kyle Ferreira
As the content manager at Upcomer, Kyle brings a lifetime of gaming and over seven years of professional writing experience to the platform. He holds a tender spot for indie games, but can sometimes be found in an FPS getting destroyed in a fruitless attempt to relive his old CS 1.6 glory days. After which he can usually be found licking his wounds in a chill game of Kenshi.