Ah, Subnautica. One of the best and worst horror stories to have graced the gaming world in the 2010s. If you’re looking for a way to deal with thalassophobia, this game will surely work wonders for you. This open-world survival action-adventure game had its humble beginnings in 2013 when Unknown Worlds Entertainment first announced it. Subnautica Bioreactor entered early access in 2014, where it remained until its official release in 2018.
One of the most important aspects of the game is finding a sustainable source of energy. Without it, it’ll be nearly impossible for you to continue playing comfortably. Different choices include the thermal plant, solar panel, nuclear reactor, and bioreactor.
While it’s not the most powerful energy source, the bioreactor is certainly the most efficient one. Let’s find out how it works and how to power it below!



What does the Bioreactor do in Subnautica?
As we’ve said before, the bioreactor is an energy source. This aspect of the game is important for powering your base, which you will eventually build.
The Subnautica bioreactor produces 1 energy per 1.2 seconds. Like all the other sources of energy, it has a maximum capacity.
Whereas the nuclear reactor has the largest capacity of 2500, the bioreactor has the second-largest capacity of 500. This is a great improvement when you compare it to the solar panel’s 75 and thermal plant’s 250.
Having an energy source like the bioreactor in your base helps power all your electronics. This also includes producing oxygen, which is important if you plan to build your base somewhere underground.
What we’re saying is that you’ll need a bioreactor if you want to have appliances such as the Fabricator and the Power Cell and Battery chargers.
Even more importantly, it powers the Water Filtration System. This is essential once you run out of Bladderfish, which also gives you hydration.
As you can see, the Subnautica bioreactor does a pretty important job in your Seabase. For that reason, you should make sure to build one as soon as you can!
How does the Bioreactor work?
The bioreactor creates energy by composting organic matter. To place it, you need to make a dedicated multipurpose room, as it can only stand in the center of this room.
For that reason, the bioreactor is a great choice of energy source for players who want to build their Seabase in areas with tons of organic matter. Examples of such areas include the Kelp and Mushroom forests.
There are different kinds of fuel that you can put into the Subnautica bioreactor. They range from flora to fauna you can find around your base. This is usually the best option as it means you don’t have to go hunting for organic matter now and then.
Of course, there are some choices of fuel that are better than others. We’ll talk a bit more about that subject later.
In any case, the bioreactor can essentially work in every biome, but the bioreactor placement is really important. However, as we said, some are better suited for it than others, so you should keep that in mind when building a new Seabase.
What is the Bioreactor made of?
Now we turn to the question of how to make a bioreactor. To build the bioreactor in the first place, you need another device known as the Habitat Builder. This device is a great help when creating your base, and we’re sure you already have it if you’re reading this article by now.
After you acquire the Habitat Builder, some new challenges await you. You need some materials to use when making the Subnautica bioreactor. This includes three pieces of titanium, a wiring kit, and some lubricant. Acquiring them all is not too hard, either.
The titanium is probably the easiest one to find. The limestone outcrops, which have a 50% chance of giving you titanium, are available in almost all biomes. The only exceptions are the Blood Kelp Zone, the Bulb Zone, Lava Lakes, Mountains, the islands, and a few others.
You can build the wiring kit with the fabricator, using two pieces of silver ore. Likewise, the fabricator can transform one piece of Creepvine seed clusters into the lubricant.
After you combine all these, you’ll have your very own Subnautica bioreactor!
Not every piece of fuel will provide the same amount of energy, though. You may find that smaller pieces such as the Acid Mushroom Spores will produce significantly less energy compared to certain fish such as the Garryfish.
With that in mind, you should be careful as to what fuel you put in your bioreactor. You don’t want to return to your Seabase only to find out that nothing works because your fuel ran out a long time ago.
Without further ado, let’s find out how to power the bioreactor!
What’s the best fuel for the Subnautica Bioreactor, and how do you get it?
Finally, it’s time to decide what the best Subnautica bioreactor fuel is.
Considering the bioreactor only accepts organic matter, we’ll need to turn to flora, fauna, corals, and eggs.
It would perhaps be best to look at a Subnautica bioreactor fuel chart if you’d like to make some conclusions yourself.
In our opinion, the best Subnautica bioreactor fuel is the abundance of fish you’re bound to have around your base. There are so many types of fish that you can catch, and since they’re part of the fauna, the bioreactor will accept them.
Overall, it seems like the best way to produce constant fuel for your Subnautica bioreactor is to build an alien containment unit for the fish. This will require yet another multipurpose room.
Finally, the fish you’ll want to be looking at grabbing is the Oculus fish, which looks quite similar to a Peeper. However, its energy production is a lot higher in the bioreactor than the Peeper at 10,080 energy per load per fish. That’s the best number out of all the fish you can grab in Subnautica.
Obtaining the Oculus can be a bit dangerous though, as you need to go to the Jellyshroom cave. The area in itself is gorgeous, but the amount of Crabsnakes that are looking to eat you for dinner is huge. They only do 35 damage, though, and usually hang around the Jellyshrooms. If you steer clear of those, you should be fine!
Just grab two Oculus fish and put them in the alien containment unit. Here, you’ll be able to breed them and thus create some renewable fuel for your bioreactor. And voila, you have a sustainable energy source in Subnautica!