To do this, follow these steps:

1. Navigate to your Library
2. Right click Subnautica and select properties
3. Click the 'betas' tab
4. Open the dropdown menu and select the 'experimental' beta
5. Click close

Now allow Subnautica to update, and launch the game when it is ready.

1. After opening Subnautica, go into the settings menu from the title screen
2. Then select "Redeem a Key" and paste in the code below:

SMHB-VC57-V748-8EGU-1EO

After applying this key, close the game and naviagte back to the 'betas' tab, and select 'none' in the dropdown menu.


You will recieve the Septic Tank in your Steam inventory, and will now be able to craft it in-game (using 1 titanium and 1 glass)!


Note; this only works on the Steam version of Subnautica, it will not work on the Epic or Playstation versions.