Just started Subnautica 2 and wondering how you get the Acidic Raion Pouch? Don't worry, this short guide will set you on the right path.
The Acidic Raion Pouch is required to craft Basic Batteries, which are needed to craft the Scanner, amongst other uses. Obtaining it requires you to first craft another item so if you are just wondering around the ocean floor trying to loot it, you won't have much luck.
Where To Find The Acidic Raion Pouch In Subnautica 2
You've probably actually already passed this material many times without knowing. The small purple gelatinous blobs that you loot the Medical Gel Sac from are also actually the source of the Acidic Raion Pouch.

However, you won't actually be able to obtain the Acidic Raion Pouch until you craft the Survival Multitool.
Crafting The Survival Multitool
To craft the Survival Multitool, simply obtain three Titanium (you'll find this all over the seabed) and then craft it in the Tools section of your Fabricator back at the pod.

The Survival Multitool will allow you to break down resources in order to obtain them, including the Acidic Raion Pouch. It's an essential item you should craft right at the start of the game.
Harvesting The Acidic Raion Pouch
Equipped with your Survival Multitool, just approach one of the purple blobs and right click to hack at it, dislodging and looting the pouch.

Tip: The Medical Gel Sac that you can loot is also really useful as it can be consumed by itself for HP or used to craft Enhanced Med Kits.
And that's it! Happy exploring.