Probably Stolen aquaculture can make you serious money, but if you also want to keep your fish alive, that’s where things get tricky. Your fish might be suffocating or your sturgeon might be starving. There’s a lot that can go wrong.
I’ll show you how to unlock fish farming and set up your RAS tank, then use cheaper fish to feed sturgeon for valuable caviar. There’s also a three-tank setup that makes the whole thing a lot easier to manage. That said, let’s begin.
Table of Contents
How to Unlock Aquaculture in Probably Stolen
There are two ways to unlock Aquaculture in Probably Stolen. If you pick the Aquafarmer start, you begin with a Recirculating Aquaculture System (RAS) already set up, plus some supplies and a few tilapia to get your farm going.
Otherwise, you have to go through Joe Wild. Unlock Water Trading first, then you can buy the aquaculture setup from him for 400 credits. That gets you the equipment you need to start farming fish.
You can later grab Aquaculture II for 1,200 credits. That unlocks eels and electric eels from the Retired Aquafarmer, plus sturgeon. You also get a couple of young eels when you buy the upgrade.
The Retired Aquafarmer also sells fertilized fish roe and other aquaculture items. From what I’ve found, she shows up on Tuesdays.
Personally, I’d stick with gutter tilapia for a while instead of jumping straight to sturgeon. They’re way cheaper to feed and they’ll help you scale up later when you’re ready for a bigger fish farm.
All Fish in Probably Stolen and Their Uses
There are six fish species in Probably Stolen, each with different benefits.
| Fish | Diet | Main use |
|---|---|---|
| Tilapia | Omnivore | Basic fish meat and breeding |
| Gutter Tilapia | Omnivore | Cheap meat and water cleaning |
| Graft Tilapia | Omnivore | Medical roe and skin grafts |
| Eel | Carnivore | Valuable luxury meat |
| Electric Eel | Carnivore | Meat and electricity generation |
| Sturgeon | Carnivore | Caviar production |
Gutter tilapia are pretty handy because they remove some heavy metals and chemicals from the water. They don’t clean out everything, though, so I wouldn’t count on them to replace every other purification method you have.
Adult electric eels can generate about 3 kJ a night and extra ones add more on top of that. Being able to charge nearby batteries makes them worth keeping around even if meat isn’t your main goal.
How to Set Up Your Aquaculture Tank
In Probably Stolen, the RAS handles the fish farming, but the slots can be a little confusing at first. You drop it down and make sure it has enough power to run overnight, then stick a water container in the Water slot and fill it. The basic setup holds about 12,000 mL. Fertilized roe goes in the fish tank area itself, not in the water container.
You can toss in some appropriate fish food right away even if you don’t have a Livestock Feed Dispenser yet, though that thing makes feeding a lot less hands-on. Add a Water Filter to help keep contamination under control as the fish get bigger. As long as they’ve got enough food and the conditions stay decent, they’ll hatch and grow night by night.
The Livestock Feed Dispenser isn’t the same as an Intake Hopper. It lets you blend food so your fish can eat it automatically. I’d grab one once you’re dealing with more than a few fish and it starts feeling like too much work.
How to Keep Fish Alive in Probably Stolen
Fish need enough water and a working RAS to stay healthy, not to mention regular food. Dirty water can also mess them up, especially the ones that don’t handle contamination well.
Why Are My Fish Suffocating?
If your fish are suffocating, look at how much water you’ve actually got versus how much all the fish in the tank need. A full 12,000 mL container doesn’t automatically mean they’re fine. Bigger fish need more water as they grow.
If you stack a bunch of sturgeon or eels, it can push the total past what the tank can handle. Hover the RAS and check the tooltip for the real requirement, then pull some fish out if it can’t keep up. Power‘s another thing: Make sure the RAS has enough juice to run overnight, because a dead battery will leave them in a bad spot.
Remember, don’t mix up suffocation with contamination damage. They can still take hits from dirty water even when there’s enough water.
What You Should Feed Your Fish
Tilapia are omnivores, but eels and sturgeon need meat. Gutterflow Pellets are the cheap option at 40 credits for 4,000 kcal, though feeding most fish too many pellets can drop their meat to Trash Grade. Gutter tilapia don’t get hit by that. Industrial Fish Feed costs more at 100 credits for 5,000 kcal and skips the quality penalty, but it slows growth to 75% of the normal rate.
Meat speeds up tilapia growth and is basically required for the carnivores. I’d just keep those carnivores fed so they don’t start going after the smaller fish in the tank.
How to Breed Fish and Fertilize Roe
Only the different kinds of tilapia will breed in captivity. Eels and sturgeon won’t. To get tilapia breeding, keep healthy adult males and females of the same type together in the tank. Once the females are fed, they’ll lay unfertilized roe. Then the males take care of fertilizing it while the roe remains in the tank. That fertilized roe eventually hatches into fry.
If your graft tilapia keep dropping unfertilized roe, make sure there’s an adult male of the same species in the tank with them. Watch your Auto Butcher settings too. If it’s culling all the males, you won’t get any fertilized eggs.
One thing worth knowing is that unfertilized graft tilapia roe can be sold as a medical item, so you don’t actually need breeding males if you’re just trying to farm that for cash.
How to Get Sturgeon and Harvest Caviar
Sturgeon unlock once you grab Aquaculture II and you can buy them from the Retired Aquafarmer. They’re expensive to keep because they need meat and take up a lot more water as they get bigger. Unlike tilapia, they won’t breed in the tank.
Healthy adult females will produce eggs. A full-grown one can hold around 525 g and the Gravid status shows when it’s at capacity. You can harvest the caviar two different ways. Using a knife means butchering the fish so you get the meat and the caviar, but that kills it.
With a Surgery Toolset, you can pull the caviar out and leave the sturgeon alive, though the surgery damages it and egg production stops until its health climbs back to at least 90%. The toolset is reusable and shows up with traders who sell medical supplies.
Caviar has a base value of 240 credits and takes up four inventory slots, so it’s a decent luxury item.
Best Fish to Farm in Probably Stolen
I’d lean toward sturgeon if you want caviar. Graft tilapia are good for producing medical items, plus gutter tilapia work fine when you just need cheap food coming in. Regular tilapia are fine for getting the farm going, but the other two bring extra upsides.
Sturgeon can make decent money, though how much you actually clear depends on how expensive they are to keep fed and watered. I wouldn’t load up a whole tank of them until you’ve got a steady meat supply ready.
A Profitable Three-Tank Fish Farming Setup
For a profitable fish farm in Probably Stolen, I’d split the setup across three tanks. This way, your cheaper fish can keep the sturgeon fed without having to buy meat all the time.
| Tank | Fish | Recommended setup |
|---|---|---|
| 1 | Gutter Tilapia | Keep at least 1 male and 3 females. Use Gutterflow Pellets and set Auto Butcher to cull surplus fish aged 10+ days. |
| 2 | Graft Tilapia | Keep 9 females and no males, then collect unfertilized roe. Use Industrial Fish Feed and cull surplus fish aged 5+ days. |
| 3 | Sturgeon and Eels | Blend meat from the first two tanks and use it to feed the carnivores. |
This is a demonstrated farming configuration, not necessarily the most profitable setup. The main upside is that the cheaper fish end up supplying meat for the sturgeon instead of you having to buy all of it.
I’d treat it as a starting point and then tweak how many fish you’re running based on how much water you’ve got and what the feed is costing you.
How to Harvest Fish and Upgrade Your Tank
A knife works if you want to butcher fish by hand. The Auto Butcher takes care of harvesting on its own. It can also grab roe depending on how you set it up.
Expand the tank to give the fish more room, but it doesn’t bump up that 12,000 mL water limit. It does push the power draw higher, so it’s worth picking up some efficiency upgrades at the same time. Hover the RAS and check the tooltip before you start upgrading. It’ll show you what’s available and what each one needs.
Common Aquaculture Problems and Fixes
Most aquaculture problems in Probably Stolen come down to a couple of basic tank conditions. It’s worth double-checking those before the whole setup turns into a money sink.
| Problem | What to Check |
|---|---|
| Fish are suffocating | Total required water and RAS power |
| Fish keep losing health | Check the water quality and make sure your fish have enough food. Too many fish can also cause problems if the tank doesn’t have enough water. |
| Roe won’t become fertilized | Adult male of the same species |
| Fish aren’t eating | Correct diet and Feed Dispenser settings. |
| Sturgeon stopped producing eggs | Health must recover to at least 90%. |
| Tank can’t hold more fish | Expand its grid, then recheck available water. |
| Fish eat their fry | Make sure adult fish have enough food. |
For me, the key to keeping an aquaculture setup manageable is not overcomplicating it. Start with a few tilapia and get their feeding sorted before you worry about anything else. Once you’ve got enough meat coming in, it makes sense to move into sturgeon. Caviar’s worth going after, just not if the whole farm ends up suffocating overnight.
