Short answer: for a full pond of 10 fish, Lava Eel earns the most if you sell what it makes as it comes (about 543g a day), followed by Blobfish (496g). If you turn the roe into Aged Roe or Caviar with Artisan, Blobfish leads at about 1,301g a day with 4 Preserves Jars, and Sturgeon Caviar makes 998g. Legendary fish earn more but you can only keep one of each.
Pick a fish and how many live in the pond to see what it produces each day.
Results
Best fish for ponds
Full pond, with your roe and Artisan settings above.
How a fish pond produces
- Daily chance: each day a pond has a base chance to make something: 8% per fish plus 15% (23% with one fish, 95% with ten). Legendary fish ponds have 50%.
- Which item: each fish has its own list of items and shares by population, taken from the fish's page on the wiki. The chance for an item is the base chance times its share.
- Extra roe: when a pond makes roe there is a 20% chance of one more, which can repeat; that adds a quarter of a roe on average.
- Prices: roe sells for 30g plus half the fish's price. Aged Roe is worth twice the roe; Sturgeon roe becomes Caviar instead. Fisher and Angler do not change roe prices.
Assumptions
- The population stays the same for the days you enter, and you collect the pond every day (an uncollected item is replaced by the next one).
- Items without a sell price (such as Golden Coconut) count as 0g.
- The wiki gives two different times between new fish for three fish: Anchovy (2 days on its fish page, 1 in the Fish Pond table), Halibut (3 or 2) and Super Cucumber (5 or 4). We use the fish page, so for these three the real time may differ by a day.
- Building a pond costs 5,000g plus materials at Robin's.