How to Get Necrolei Cyst & Strong Acid in Subnautica 2
TL;DR
- Necrolei Cyst is harvested from the tops of Stilt Orb plants using the Survival Multitool.
- Best location: the jellyfish forest near the Old Habitat, roughly 300–350 meters north of the Lifepod.
- Strong Acid is crafted at the Processor — not the Lifepod Fabricator. You need 2x Necrolei Cyst per bottle.
- Scan the Processor blueprint at the Old Habitat before heading home to build it.
- Strong Acid is needed for Fiber Mesh, Power Cell, Advanced Battery, Rebreather, and more.
- Collect at least 4 Necrolei Cysts per trip to cover the Rebreather recipe (requires 2 Strong Acid).
- Alternate recipe: 1x Sulfur + 1x Gold — but both require the Heat Tolerance Adaptation to farm reliably.
Strong Acid is one of the first mid-game crafting walls you will hit in Subnautica 2. The moment you try to craft a Rebreather, a Power Cell, or a Fiber Mesh, you will find that Strong Acid is required — and that you have no idea where to get it. Unlike Mild Acid, which comes from the Acidic Raion plants found everywhere in early caves, Strong Acid uses a completely different plant from a completely different biome. That plant is the Necrolei Cyst.
This guide covers exactly what Necrolei Cyst looks like, where to find it, how to harvest it, and how to turn it into Strong Acid using the Processor. Before heading out, make sure your base is set up — if you have not yet built one, check our guide on how to unlock the Habitat Builder.
What Is Necrolei Cyst?
Necrolei Cyst is a plant resource harvested from alien flora called Stilt Orbs. These are green, bulb-shaped plants that grow on long pink tentacle-like stalks, with a small flower or cyst blooming from the very top. The cyst at the top — that is the Necrolei Cyst you need to collect.
Here is how to identify them:
- Shape: A green fruit-like orb sitting on pink tentacle stalks, with a star-shaped orange-green cyst or small turquoise flower growing from the tip.
- Biome clues: They grow in a jellyfish forest biome. When you start seeing blue-hued water, teal Jelly Lei structures hanging on either side of you, and big plants with pink tendrils, you are in the right area.
- At night: The cysts glow with a pinkish light, making them significantly easier to spot in dark water. Nighttime runs in this biome make finding them much faster.
- During the day: The glow is less obvious but the distinctive tall stalk and rounded bulb shape still stand out once you know what to look for.
You need the Survival Multitool to harvest Necrolei Cysts — they cannot be picked up by hand. Use the Multitool to cut the cyst off the top of the Stilt Orb. Each plant gives one Necrolei Cyst.
Where to Find Necrolei Cyst in Subnautica 2
The Jellyfish Forest Near the Old Habitat (~300–350 Meters North)
The primary and most accessible Necrolei Cyst location is in the jellyfish forest biome near the Old Habitat colony ruins, roughly 300 to 350 meters north of the Lifepod.
To get there from the Lifepod:
- Swim north from the Lifepod.
- Watch for the environment to change — you will start noticing a blue-ish hue to the water and teal Jelly Lei structures appearing on either side.
- Keep going until you reach the Old Habitat ruins. Turn left toward the big plants with pink tendrils.
- Near those large pink-tendril plants, look for the Stilt Orbs — green bulbs on pink stalks with a small flower or cyst on top.
- Equip your Survival Multitool and cut the cyst from the top of each plant.
Necrolei Cysts grow in clusters in this area, usually in groups of three or four close together. One good pass through the jellyfish forest can give you 10 or more Cysts, which is more than enough for several Strong Acid crafting sessions.
NOA will actually send you to the Old Habitat area as part of the early blackbox mission chain, so you will end up here naturally during story progression. Bring your Scanner when you make this trip — there is a Processor machine inside the Old Habitat that you need to scan to unlock its blueprint (more on this below).
Near the Blackbox — Quaker Habitat
Another early confirmed location for Necrolei Cysts is near the open area outside the cave systems at the Blackbox — Quaker habitat. The plants here are tall and bright, looking somewhat like glowing jellyfish or tall illuminated flowers. Scan one first before harvesting — this adds the Necrolei Cyst to your databank and may also trigger Strong Acid as a discoverable recipe in the Processor once you have it built.
General Location: The Blue and Purple Coral Plant Area
Multiple sources confirm that Necrolei Cysts are found in the area with blue and purple coral plants, approximately 350 meters north of the Lifepod. This overlaps with the Old Habitat and jellyfish forest area. If you are heading north and start noticing the distinctive turquoise and blue coral formations alongside the jellyfish-like hanging structures, you are in the right zone — start looking for Stilt Orbs in that area.
For a quick reference, our Subnautica 2 Quartz guide also references this northern biome for multi-resource farming runs, so combining a Necrolei Cyst trip with other resource gathering is very efficient.
How to Harvest Necrolei Cyst
Once you find a Stilt Orb:
- Scan it with your Scanner first if you have not already — this unlocks it in your databank.
- Equip your Survival Multitool.
- Aim at the cyst growing from the top of the plant.
- Use the Multitool to cut it loose. It will drop into your inventory.
Each Stilt Orb gives one Necrolei Cyst. Since the recipe for Strong Acid requires 2 Necrolei Cysts per bottle, and the Rebreather alone requires 2 bottles of Strong Acid, you need at least 4 cysts just for that one item. Collect 8 to 10 on every trip to build up a proper stockpile for all the recipes ahead.
Be aware that this area can have aggressive creatures patrolling nearby. Bring First Aid Kits as backup. For crafting First Aid Kits, check our guide on how to get Fiber and Fibrous Pulp — Fiber Mesh is the key ingredient.
Step 1: Unlock the Processor Blueprint
Strong Acid cannot be made at the Lifepod Fabricator. It requires a Processor — a base machine that processes raw materials into refined components. Before you can build one, you need to scan a broken Processor to unlock its blueprint.
The easiest place to find and scan a Processor is inside the Old Habitat colony ruins, the same area you are visiting for Necrolei Cysts. When you enter the building, look in the second room on the right side — the Processor machine is there. Scan it and the blueprint unlocks immediately.
This is why the Old Habitat trip is so efficient: you scan the Processor, collect the Necrolei Cysts, and make progress on any NOA mission all in a single dive.
Step 2: Build and Power the Processor
Once back at your base, build the Processor inside a room using the Habitat Builder. The crafting recipe requires:
- Titanium x2 — found in caves and seafloor deposits near the Lifepod.
- Copper Wire x1 — craft at the Fabricator using 2 Copper Ore.
- Mild Acid x1 — craft at the Fabricator using 2 Acidic Raion Pouches and 1 Copper Ore.
The Processor is a power-hungry machine. It uses 10 energy units per second while running. Make sure your base has enough Solar Panels active before you start processing. Running it at night when solar output drops is inefficient — load a batch before going out to dive and let it process while you are away. See our guide on what to build in your base first for base power planning tips.
You need a Titanium guide too? Check our Titanium farming guide for the fastest ways to stock up.
Step 3: Craft Strong Acid at the Processor
With Necrolei Cysts in your inventory and the Processor powered up, here is how to make Strong Acid:
- Interact with the left side of the Processor.
- Select Change Recipe and scroll to find Strong Acid under the Refinement section.
- Select it, then choose Load. The Processor automatically pulls 2 Necrolei Cysts from your nearby storage.
- Wait 30 seconds for the processing cycle to complete.
- Interact with the right side of the Processor to collect your Strong Acid bottle.
One batch: 2 Necrolei Cysts = 1 Strong Acid. The finished product is a small flask with a yellow-green liquid. If nothing appears in the output slot, the most common reasons are insufficient base power, the wrong recipe selected, or only one Necrolei Cyst loaded instead of two.
The Alternate Recipe: Sulfur + Gold
There is a second recipe for Strong Acid: 1x Sulfur + 1x Gold. However, this is not a practical early-game option for most players. Both Sulfur and Gold are found in the volcanic lava biome to the east — and you cannot safely survive there without the Heat Tolerance Adaptation, which is itself locked behind story progression and Bloom Infestation clearing.
The Necrolei Cyst route is faster, cheaper, and available earlier. Only consider the Sulfur and Gold path if you already have Heat Tolerance unlocked and happen to have surplus materials from farming that biome for other reasons. For information on clearing Bloom Infestations to unlock the Heat Tolerance Adaptation, see our guide on how to harvest large resource nodes and clear Bloom Biofilm.
What Is Strong Acid Used For in Subnautica 2?
Strong Acid is involved in some of the most important mid-game crafting recipes. Here is a full breakdown of the key uses:
Fiber Mesh
Fiber Mesh requires 2x Fiber and 1x Strong Acid. This is one of the most immediate uses you will have for Strong Acid. Fiber Mesh goes into the Rebreather and the Improved Fins — both critical exploration upgrades. The Rebreather reduces oxygen consumption at depth, letting you dive deeper for longer. For the Fiber side of the recipe, see our guide on how to get Fiber and Fibrous Pulp.
Power Cell
A Power Cell requires Strong Acid alongside other materials. Power Cells are needed to craft and operate the Tadpole — the first vehicle in the game that massively expands your diving range, speed, and protection. Getting the Tadpole is one of the biggest early progression milestones. Without Strong Acid, you cannot build a Power Cell. Without a Power Cell, no Tadpole.
Advanced Battery
Advanced Batteries are upgraded versions of the Basic Battery. Strong Acid is a required ingredient. Advanced Batteries feed into more complex tools and base equipment in the mid-to-late game.
Dedicated Core
Dedicated Cores are advanced electronic components needed for base facilities and high-tier crafting chains. Strong Acid appears in their recipe as well.
Rebreather
The Rebreather itself requires Fiber Mesh (which needs Strong Acid) to craft. Combined with the direct Strong Acid requirement in Fiber Mesh, this means you need at least 2 bottles of Strong Acid, or 4 Necrolei Cysts, just for the Rebreather. Always collect extra on your first trip north.
How Many Necrolei Cysts Should You Collect?
Here is a practical guide for how many Necrolei Cysts you need for the most important early recipes:
- Fiber Mesh x1 — 1 Strong Acid = 2 Necrolei Cysts
- Rebreather — 2 Strong Acid (via 2x Fiber Mesh) = 4 Necrolei Cysts
- Power Cell x1 — 1 Strong Acid = 2 Necrolei Cysts
- Full early loadout (Rebreather + Power Cell) — at least 6 Necrolei Cysts
Collect 8 to 10 Necrolei Cysts on your first dedicated trip. That covers the Rebreather and Power Cell with some buffer left over for Advanced Batteries and other recipes you will hit shortly after.
Necrolei Cyst Farming Tips
- Combine the trip with the Processor scan. The Old Habitat has both the Processor blueprint and the nearby jellyfish forest. One trip north handles both objectives and saves a second dive.
- Scan before you harvest. Scanning the Necrolei Cyst plant adds it to your databank and may unlock the Strong Acid recipe in the Processor. Do this before cutting the cyst off.
- Farm at night. The pinkish glow of the Necrolei Cysts is much more obvious in dark water. Night runs in the jellyfish forest are faster because the plants are easy to spot from a distance.
- Bring a Portable Locker. The jellyfish forest is dense with Necrolei Cysts and other scannable plants. A Portable Locker lets you carry more without cutting the run short.
- Stock up on the first visit. The area has some aggressive creatures. Getting 8–10 cysts in one trip means you do not have to swim back through that zone again just because you needed two more.
- Load the Processor before going out. Queue up a batch of Strong Acid before you leave your base for a dive. The 30-second processing time finishes while you are out, and you come back to finished product waiting for you.
- Bring the Standard Air Tank. The jellyfish forest requires diving down to roughly 90–100 meters in some areas. Having the Standard Air Tank equipped makes the trip much less stressful. Not sure where to get Silver for the Air Tank? See our Silver guide.
Summary: How to Get Strong Acid Fast
- Craft a Survival Multitool if you do not already have one.
- Equip the Standard Air Tank before diving — the jellyfish forest is around 90–100 meters deep in places.
- Swim north from the Lifepod for 300–350 meters toward the Old Habitat ruins. Watch for the blue-hued jellyfish forest biome to appear.
- Inside the Old Habitat, scan the Processor machine to unlock the blueprint.
- In the jellyfish forest nearby, find the Stilt Orbs — green bulbs on pink stalks with a cyst on top. Scan one first, then cut the cyst off with the Survival Multitool.
- Collect at least 8–10 Necrolei Cysts before heading home.
- Back at base, build the Processor inside a powered room using the Habitat Builder.
- Interact with the left side of the Processor, select Strong Acid, and load 2 Necrolei Cysts. Wait 30 seconds and collect from the right side.
- Use your Strong Acid to craft Fiber Mesh, a Power Cell, and eventually the Rebreather.
Strong Acid feels like a mysterious wall until you know the route. Once you have done one jellyfish forest run, the whole mid-game crafting chain opens up — better fins, the Rebreather, the Power Cell, and ultimately the Tadpole all become achievable in quick succession.
For more crafting and progression help, check out our guides on how to get Rubber, how to get Titanium, best early upgrades and progression path, and our full co-op multiplayer guide. Grab the game on Steam or Xbox Game Pass.
