I watched the power bar crawl toward zero as the base lights stuttered. I swam out, heart in my throat, and found a battered machine that promised the difference between blackout and comfort. You can be two scans away from that same revelation.
I’ve spent hours hunting blueprints so you don’t have to. I’ll walk you through the three fragment sites, the build costs, and the smartest fuel choices—so you can stop babysitting reactors and start exploring.
People stash spare tools in a garage; the sea tucks blueprints into odd corners — All Bioreactor blueprint locations in Subnautica 2
You need to scan three broken bioreactor machines with your Scanner to assemble the blueprint. I’ll point you to each machine and tell you what to expect when you get there.
Where are the bioreactor blueprint fragments in Subnautica 2?
- Chap’s Blackbox cave — 220 meters south of the Lifepod. Follow the stone pillars until you find the cave entrance. Inside is a cramped living compartment with scattered items you can scan: a bioreactor, a repair tool, furniture, and a biobed you can use for extra inventory.
- Metal crate east of the Lifepod — ~390 meters east. Head just north of the volcanic ocean biome to a field of metal ruins. The bioreactor fragment sits in a large metal crate next to a coral dome. Expect tight passages and wreckage to swim around.
- Old Habitat POI — ~380 meters north of the Lifepod. Enter through the northwest passage or approach from below and surface through a hole in the floor. The bioreactor is in the Old Habitat’s western wing. Scan carefully: the POI has several wrecked machines you can tag with the Scanner for extra fragments.
Scan all three and the blueprint drops into your Fabricator/Blueprint menu. If you play on Steam or the Epic Games Store, the in-game Scanner is the same—so you won’t need mods or external tools to do this.
My toolbox has spare wire; your base needs one reliable power node — How to build a Bioreactor in Subnautica 2
After scanning, craft the bioreactor with the Habitat Builder under Interior Facilities → Power. You’ll need:
- Titanium Ingot ×2
- Copper Ingot ×2
How do I build a bioreactor?
Both ingots are made with a Processor. Broken processors exist to scan inside the Old Habitat if you haven’t found one. Each ingot requires three raw titanium or three raw copper and takes about 30 seconds to process. Expect roughly two minutes to get all four ingots ready.
Place the bioreactor inside your base where you can feed it easily. I recommend near storage and the base console so you can toss fuel in without making a second trip outside.
A kitchen has a shelf of preserved jars; your bioreactor needs predictable fuel — How to get Bioreactor fuel in Subnautica 2
The bioreactor accepts any organic item you drop into its feed slot. It operates in three modes: Off, Normal (10 power points), and Overdrive (20 power points, burns fuel twice as fast).
What fuels a bioreactor?
Early-game the best bet is Biofuel Blocks. You craft one inside the Processor using combinations like:
- Fibrous Pulp ×5
- Pent ×3
- Crab feces ×2
Biofuel blocks burn much slower than raw organic items. Toss a few blocks in and you’ll get steady output for longer—think of the reactor like a campfire: small, controlled logs keep the heat without constant tending. When you need burst power, switch to Overdrive, but be ready to restock fast.
If you want hands-off reliability, stack blocks and set the machine to Normal. The processor system behaves like a Swiss watch once you wire it into base storage and an automated feed routine.
I’ve named the areas and tools that get you there: the Lifepod, Chap’s Blackbox, Old Habitat POI, Scanner, Habitat Builder, Processor, and the in-game Fabricator. Unknown Worlds Entertainment built the base systems; Steam and Epic distribute the game.
Ready to stop watching the meter and start exploring the deeper wrecks—what would you raid first for fuel and why?