ONCE HUMAN: Acid Production Calculator & Math Breakdown

Every player in Once Human can produce Acid. This is crucial because Acid is necessary for smelting high-grade metal ingots (e.g., aluminum and tungsten), which are essential for crafting and upgrading equipment. Acid production math might be overwhelming for beginners, so I created a convenient Acid Production Calculator. There is also a full breakdown of the Acid production math in this guide, so make sure to check it out.

Acid Production Calculator

A Simple Acid Farm (Building Guide)

Not so long ago I posted a video tutorial on building an Acid farm on my YouTube channel.

Where You Can Produce Acid

To produce Acid, you need to extract Polluted Water using Water Pumps. This is only possible in so-called Contaminated (or Polluted) Areas. In such zones, your character’s backpack starts blinking, and their sanity decreases, which reduces maximum HP.

To locate contaminated zones easily, use an interactive map via the link

1. Select the scenario you are currently playing. This is important, as the “Way of Winter” scenario has a different world map.
   
2. Open the “Filter” panel and go to the “Search” tab.
   
3. Type “contaminated area” into the search field and press Enter. This way you will get a list of all contaminated areas on the selected map.

Setting Yields

After you place a Water Pump within a contaminated area, you must set its yield. By default, all the pumps extracts Dirty Water, so you must switch the yield to Polluted Water. To do this, open the pump menu, and press “Set Yield” (G). In the list, select Polluted Water.

You must also set yield for a Large Water Filter. By default, it processes Dirty Water into Pure Water, so you must switch this to the processing Polluted Water into Impure Acid.

Acid Production Process & Math

To produce Acid, you must extract Polluted Water with Water Pumps and process it into Impure Acid using a Large Water Filter (before it was called “Osmosis Water Purifier“). Afterward, combine Impure Acid with Pure Water in a Brewing Barrel to get Acid. For maximum efficiency, follow these ratios:

• 10 Water Pumps (Polluted Water),
• 2 Water Pumps (Dirty Water),
• 2 Brewing Barrels,
• 1 Large Water Filter (Pure Water),
• 1 Large Water Filter (Impure Acid).

Here’s a detailed breakdown:

• Each Large Water Filter processes 2 units of Polluted Water into 1 unit of Impure Acid per 15 second (8 Polluted Water → 4 Impure Acid / minute; 480 Polluted Water → 240 Impure Acid / hour).
• This means, to fully utilize its production capacity, you need to provide 480 Polluted Water / hour, resulting in 240 units of Impure Acid / hour.
• A single Water Pump extracts 4 units of Polluted Water every 5 minutes or (4 units × 60 min ÷ 5 min) 48 units per hour.
• This means you need 480 ÷ 48 = 10 Water Pumps for each Large Water Filter.
• To produce 1 unit of Acid in a Brewing Barrel, you need 10 units of Impure Acid, 10 units of Pure Water, and 5 minutes of real time (1 Barrel = 12 Acid / hour).
• This mean, to fully utilize the production capacity of a single Brewing Barrel, you must provide 120 units of Impure Acid / hour and 120 units of Pure Water / hour.
• Since 1 Large Water Filter produces 240 units of Impure Acid per hour, you need 240 ÷ 120 = 2 Brewing Barrels.
• You must also supply these 2 Brewing Barrels with 240 units or Pure Water per hour. A single Water Pump extracts 24 units of Dirty Water per 5 minutes (288 Dirty Water / hour → 144 Pure Water), so you will need 240 * 2 / 288 = ~1,66 = 2 Water Pumps, which will extract Dirty Water, and 1 Large Water Filter, which will process it into Pure Water.
• Thus, the setup produces (240 Impure Acid / 10) 24 units of Acid per hour.

This setup consumes 160 Watts of power. If you generate enough electricity using Electric Eels or Memetic Specializations, you can scale up to 2 such setups in your base, yielding 48 units of Acid / hour (1152 Acid / day).

How To Unlock the Required Facilities

Press “O” to open the Memetics and go to the “Logistics” tab. Starting from the week 2, you can unlock the branch that includes Rainwater Collection System, Water Tank, filters and pumps.