Direct answer: In Slime Rancher (and Slime Rancher 2), Deep Brine is obtained by using a Pump in the Dry Reef area. Deploying a Pump in that specific location yields Deep Brine, which is the standard method to obtain this resource. Alternative methods include finding Deep Brine in treasure pods opened with treasure crackers, but the primary and most reliable source is the Pump at The Dry Reef.

Details and options:

• Primary method: Build a Pump and place it in The Dry Reef. The Pump will harvest Deep Brine over time; higher-quality pumps can harvest more efficiently, but the basic Pump suffices since Deep Brine is relatively common. You’ll need to unlock the Novice Pump blueprint (via the Lab expansion) by paying the required Newbucks, then craft the Pump and deploy it in The Dry Reef.

• Secondary method: Treasure pods. Deep Brine can also be obtained from treasure pods in the Lab, The Dry Reef, and the Ancient Ruins. Upgrading treasure crackers (MKII at 20 gadgets, MKIII at 50 gadgets) enables opening more pods that yield Deep Brine. This path is optional and depends on your gadget progress and pod availability.

Practical tips:

• If you’re early game and want a straightforward approach, focus on crafting and placing a Novice Pump in The Dry Reef and check back after each in-game hour for Deep Brine yields.

• If you enjoy exploration and pod hunting, search for treasure pods across the Lab, Dry Reef, and Ancient Ruins, upgrade your treasure crackers to access higher-tier pods that grant Deep Brine.

If you’d like, I can tailor these steps to your current progress (which game version you’re playing, whether you’re on Slime Rancher or Slime Rancher 2, and what expansions you have).