For the Atomic Heart animal tank puzzle, you'll need to complete an experiment of some kind that involves turning valves on tanks filled with cows, pigs and chickens. It's not exactly clear what turning these valves does at first, but you will need to solve this puzzle if you want to progress further into the Cold Workshop to grab the Cold Canister as part of the "In an Overgrown Park" mission. Essentially, you'll need to turn the valves on the animal tanks to fix what's displayed on the central terminal in the lab. Again, progression isn't especially clear, but we'll explain exactly how you solve the animal tank puzzle in Atomic Heart below. Word of warning to any vegetarians or people who care about animal welfare… you may want to stop reading here, though we'll only be repeating what happens in Atomic Heart itself.
What to do in the Atomic Heart animal tank puzzle
Make sure you also know how to solve all Atomic Heart lockpicking puzzles too
The Atomic Heart animal tank puzzle is about turning the valves so that the respective icons of each cow, pig and chicken on the screen go from red to green. However, because it's not clear which icon links to which tank, and the scanner in Atomic Heart scanner is no use in gaining new info, there can be some trial and error involved. The game doesn't really have a pattern to follow, so we put together this map to help you correspond each tank and valve to each symbol.
How to solve the animal tank puzzle in Atomic Heart
This means that if you didn't turn any valves yet, you'll have to turn every one except 2 and 6 (the top left chickens and the cow by the entrance vent on the right), which start off green as default. Otherwise, use the map to highlight which ones still need turning.
The easy way to tell is if a valve turns clockwise, that'll turn the corresponding light green. If you turn it counterclockwise, you've triggered the wrong one and need to turn it back. Use that as a way to instantly confirm you've gotten a choice right!
Once you've gotten it all turned to green, the tanks will all automatically activate and… blend the animals into paste. There's no way to progress without doing this, as once the puzzle is complete, the northern door (marked by the outwards arrow) will open and allow you to move on towards the Cold Canister. Turns out that the animals are being converted into Neuropolymer which fuels abilities like your Atomic Heart telekinesis and the Atomic Heart sprint upgrade, though you won't get any as a reward. If you've not yet been to the Pesticide Workshop, you'll need to move the Atomic Heart yellow canister along some train tracks, which is quite a long puzzle to solve.
