Deep Shrooms in Subnautica are mid‑ to late‑game plants that grow in a few deep biomes and are mainly used for crafting Hydrochloric Acid and Polyaniline, which then unlock important upgrades.

What Deep Shrooms Are

Deep Shrooms are a special type of mushroom that only spawns in deeper biomes rather than in safe shallows or early areas.

They are interactable plants that you can either pick or cut with your knife, and cutting them yields extra seeds so you can farm them later in an exterior growbed.

Best Biomes To Find Them

Players consistently report finding Deep Shrooms in several deep or late‑game regions.

The most commonly mentioned biomes are:

  • Blood Kelp Zone and Blood Kelp Trench, including relatively “safe” clusters on the edges.
  • Inactive Lava Zone and other 500 m+ depth areas for late‑game harvesting.

Easy / “Safe” Locations

Multiple guides point to safer routes that avoid the worst predators while still reaching Deep Shrooms.

Common advice includes:

  • Travel from the Mushroom Forest out into the nearby Blood Kelp Zone; look near a crater or trench edge where a large patch of Deep Shrooms sits at roughly 200–300 m depth.
  • From near your starting Lifepod, head toward the northern Blood Kelp biome, park your Seamoth shallow (around ~280 m), and search the seafloor for clusters so you don’t need max depth modules.

What They’re Used For

Deep Shrooms are a key ingredient in several high‑tier recipes.

Typical uses include:

  • Crafting Hydrochloric Acid by combining Deep Shrooms with Salt.
  • Upgrading that into Polyaniline, which is then used for advanced suit and vehicle upgrades that boost survivability and power systems.

Quick Tips & Forum Wisdom

Community discussions emphasize that players often search too shallow when hunting Deep Shrooms.

A few recurring tips:

  • Go deeper than early biomes; if you are under 200 m, you are probably not in the right place yet.
  • Bring a Seamoth with at least a basic depth module and a rebreather, then grab several shrooms so you can start a farm and never need to go back into danger just for acid.

Information gathered from public forums or data available on the internet and portrayed here.