Probably Stolen fish guide: aquaculture
Fish are raised in a Recirculating Aquaculture System (RAS): a water tank, power, filters and a feed dispenser around a grid of fish. Tilapia is the starter species, eels and sturgeon are higher-value options, and every species needs enough clean water and food to grow. Butcher fish once they reach their adult or elder stage and before old age.
How do you start fish farming?
- The Aquafarmer specialization starts with Recirculating Aquaculture Systems, a stock of Tilapia and fish food, and a higher starting rent.
- The Aquaculture network upgrade (400 credits) sends a retired aquafarmer weekly, selling fish farming equipment and fertilized roe, and gives you an Aquaculture Starter Kit.
- Aquaculture II (1,200 credits) makes the aquafarmer bring bigger, more profitable fish each visit and gives you two young eels immediately.
What does a RAS need?
The Recirculating Aquaculture System (base value 300) needs a RAS Water Tank, a power source and filters to keep the water clean. The tank also has a dispenser slot for a Livestock Feed Dispenser. An Auto Butcher can be installed in the RAS. Each fish has a water need that grows with its life stage, and the tank shows “Water: X ml, needs Y ml”.
- If the tank holds less than half the water the stock needs, the fish die.
- Between half and full, fish lose health in proportion to the shortage.
- Waste (organic waste as a share of tank water) hurts fish above 3% and kills at 8% for standard tilapia. Graft Tilapia is twice as sensitive. Gutter Tilapia ignores waste.
- A powered tank heals fed fish by 10% of their maximum health each night when nothing is hurting them.
Which fish can you raise?
| Species | Diet | Adult weight (stage start day) | Old age | Notes |
|---|---|---|---|---|
| Tilapia | Omnivore | 450 g (day 8), 600 g elder (day 13) | day 27 | Breeds; grows 25% faster on meat |
| Gutter Tilapia | Omnivore | 450 g (day 10), 600 g (day 16) | day 33 | Ignores waste, takes heavy metal, chemical and physical contaminants out of the water, tolerates Gutterflow Pellets; less meat per feed |
| Graft Tilapia | Omnivore | 450 g (day 8), 600 g (day 13) | day 27 | Needs clean water; skin becomes Tilapia Skin Graft, roe is medical |
| Eel | Carnivore | 1,400 g (day 10), 2,400 g (day 18) | day 36 | Does not breed; luxury fillets |
| Electric Eel | Carnivore | 1,400 g (day 10), 2,400 g (day 18) | day 36 | Charges its RAS battery and adjacent batteries each night |
| Sturgeon | Carnivore | 3,500 g (day 18), 5,000 g (day 34) | day 80 | Always female; caviar |
Life stages are Roe, Fry, Juvenile, Adolescent, Adult and Elder. Tilapia starts as roe on day 0, becomes fry on day 1, a juvenile (50 g) on day 3, an adolescent (200 g) on day 5 (day 6 for Gutter Tilapia), an adult on day 8, and an elder on day 13. After the old-age day each night carries a 50% chance of death.
What do fish eat?
Fish eat when their hunger falls below 75% of the maximum, and the dispenser fills them up to its target (default 85%). Growth pauses while a fish is below about 38% of maximum hunger.
| Feed | Who can eat it |
|---|---|
| Meat (from the dispenser) | Omnivores and carnivores |
| Other food | Omnivores |
| Gutterflow Pellet (40 credits) | Omnivores only |
| Industrial Fish Feed (100 credits) | Omnivores and herbivores |
Industrial Fish Feed slows growth (up to 25% slower depending on the share in the diet), and meat speeds tilapia up by 25%. Gutterflow Pellets are cheap calories, but meat turns Trash Grade (not food, -75% value) once pellets exceed 25% of a fish’s diet. Gutter Tilapia is not penalized by pellets. Starving fish stop growing and eventually die.
How does breeding work?
Only the three tilapia types breed. Each night a fed adult female (hunger at least 50% of maximum) has a 15% chance to lay a clutch of roe. Roe becomes fertilized when a fed adult male of the same species is in the tank, then hatches into fry the next day. Fry become juveniles two days later. The clutch has its own water need (“Needs X ml for the whole clutch”), so keep room and water for it. Beware predation: a hungry omnivore or carnivore (below 75% hunger) eats live roe, fry or fish that weigh no more than 20% of its own weight, so keep the feed dispenser stocked.
What do fish produce?
Butchering a fish gives fillet pieces. They are split by calories into the largest sizes that fit.
| Item | Calories | Base value |
|---|---|---|
| Tiny Fish Fillet | 100 | 13 |
| Small Fish Fillet | 200 | 26 |
| Fish Fillet | 400 | 57 |
| Large Fish Fillet (luxury) | 900 | 143 |
| Small Eel Fillet (luxury) | 250 | 68 |
| Eel Fillet (luxury) | 500 | 136 |
| Fish Scrap | n/a | 4 |
Other products: Tilapia Roe (30), Gutter Tilapia Roe (15), Graft Tilapia Roe (60, medical), Tilapia Skin Graft (24, medical, closes a wound), Sturgeon Roe (120) and Caviar (240). Graft Tilapia skin gives a graft per 200 g of body weight.
Sturgeon eggs can be taken from a living fish with surgery tools or collected in full at slaughter. The first ten jars from surgery are Caviar, then the next six alternate between Caviar and Sturgeon Roe. Surgery costs the fish health, so let it recover.
When should you butcher fish?
Butcher once a fish reaches the stage weight you want and before old age. Bigger fish give more calories, and calories convert into larger, better-paying fillets (a Large Fish Fillet is worth more per calorie than tiny ones). Eels are worth the most per fish. Keep breeding stock separate: the Auto Butcher can collect unfertilized roe, skips fish marked with a Marking Pen, and can be set to keep breeders.
FAQ
Can I put eels with tilapia? Eels are carnivores and eat any live fish that weighs 20% of their own weight or less, so young tilapia in an eel tank are at risk. A separate tank is safer.
Why did all my fish die overnight? Check the water: too little water for the stock, waste above 8% (or 4% for Graft Tilapia), or no power.
Do I need filters? Yes. The RAS description says it needs a water tank, power and filters to keep the water clean.
Can I feed fish with rats? Carnivores accept meat from the dispenser, including rat meat.