Fish can be used as an alternate form of creating food for the Chef, or just kept as pets if you're wasteful.

Fish are kept in four types of Aquariums.

Water Level: Each fish requires 50 units of water to live. If the tank falls below this number, there is a 50% chance each tick for a fish to die. A tank with a major leak loses 10u water per tick, and a minor leak 1u. Leaks can be repaired with a silicate sprayer for 2u silicate.

Laying Eggs: Your fish will lay an egg each tick if there are at least 2 fish, 2 food, less than 5 filth, and room for more eggs. A fish tank can hold as many fish eggs as it can fish. Both parents in the tank can generate eggs, there are no hybrids however. There is a 25% chance that any egg will not belong to any species and won't hatch (a “dud”). Eggs will not hatch on their own and need to be removed from the tank, then placed back inside. A light will turn on if there is at least one egg waiting for harvest.

Food: The tank begins with 10 food and tops off completely when you use the fish food container. Each tick, there is a 50% chance fish will eat. If they do, lower food by 0.01 per fish. If your fish lay an egg, they consume 2 food. If food is below 2, there is a 25% chance a feeder fish will die and raise the tank food by 1. An indicator turns yellow if food is under 5, and red under 2 food. Fish cannot die of starvation.

Filth: Your tank starts with 0 filth. Each tick, the following occurs.

• If a fish dies due to lack of water, gain 2 filth.
• If there is 10 filth, 30% chance to kill a random fish.
• If there are no fish and less than 7.5 filth, 15% chance to gain 0.05 filth.
• If the fish ate this cycle, 25% chance to gain 0.1 filth per fish, 75% chance to gain 0.1 filth total.
• If the fish did not eat, gain 0.1 filth.
• For each catfish in the tank, 30% chance to lower the filth by 0.1.

For the fish tanks, you'll need the appropriate circuit boards. Head up to cargo and order the Aquaculture supply or the Exotic Fish crates. The former has the circuitboards for regular fish tanks while the latter has the circuit board for a wall tank. Column tanks can be made with the right research by R&D. Afterwards, refer to the Machine Construction page to learn how to build a machine frame. Remember that wall tanks and column tanks count as see-through walls so if you want to replace an actual wall with the wall tank, remove the wall and place the machine frame in its place before assembling the wall tank. Unlike regular machines, wall tanks and fish tanks can't be unbolted and will instead be disassembled into a glass sheet if you try wrenching them.

Insert the Fishtank filter circuitboard into the wired machine frame, then add 4 glass sheets. Finally, use a screwdriver on the frame to assemble it.

Insert the Large Fishtank filter circuitboard into the wired machine frame, then add 10 glass sheets. Finally, use a screwdriver on the frame to assemble it.

Insert a Column Fishtank filter circuitboard into the wired machine frame, then add 50 glass sheets and 10 metal sheets. Finally, use a screwdriver on the frame to assemble it.

So you're a chef and you want to expand into seafood or make a full on sushi bar? Well it's easy!

First you want to acquire some glass. Then you want to make several wall-mounted aquariums (NOT fishtanks or bowls) and fill them with water. You will want to make more or less tanks based on the variety of fish you have, you can intermix fish, but it is easier to manage if you keep them separate (e.g. salmon in one tank, carp in another and shrimp in a third). Put in 2 of any kind of fish egg (which you bought from the pet vendor near arrivals) and feed them immediately. After a few minutes of waiting and feeding (don't worry, the fish food is infinite) you want to harvest the eggs with your fish egg collector which you got from your fish care kit which was purchased from the pet vendor. Once collected immediately feed the eggs back into their respective fish aquarium and wait a few more minutes, feeding as soon as the yellow/red light appears. Then harvest the eggs then harvest the fish themselves until there are 2-3 left. Cut up all fish that can be cut up, boil your shrimp, and turn them to sushi/steak. See the food guide for more info.

• Shrimp is the easiest to deal with because it requires no butchery.
• Catfish help offset filth.
• Sharks can be farmed for teeth, use a wirecutter to remove them.
• Glo-Fish cause the tank to give off light even without power.