How It Works

Math Questions

Choose a grade from K to 9 and answer math questions to earn coins. Correct answers give coin rewards, and wrong answers move you to the next question.

Coins

Coins buy fish, food, tanks, passes, and koi room items. Fish do not add coin bonuses; rewards come from the math questions.

Aquariums And Game Saves

Each aquarium is its own game save. New Aquarium makes another aquarium without deleting your older ones. Save Selected Aquariums asks which aquariums you want to save; type one number, several numbers like 1,3, or ALL. Then give that saved group a save name and password. Add Saved Aquariums uses the same save name and password to add that saved group back into your aquarium list without deleting the aquariums already there.

Fish, Food, And Tanks

Fish start small and grow over time. Bigger fish need more tank space. Food is eaten slowly. If the tank runs out of food, emergency feeding costs coins and can create debt if you cannot pay. New fish get numbered names like minnow1, minnow2, or sankekoi1, and Rename Fish lets you change any fish name later.

Tank Space

Small, medium, big, large, and koi tanks hold different amounts of fish space. Better or larger fish take up more room. If fish no longer fit, you may need a bigger tank or release fish.

Koi Room

The koi room unlocks later with a pass. Koi are separate from regular fish and need koi tanks. Koi tanks are bought in the koi room, and the largest koi tank gives unlimited koi space. Koi breeding also happens in the koi room: choose two adult or giant koi, pay the breeding cost, and a baby koi hatches. You can also use Random Mix From Grown Koi to let the game choose two grown koi and a random parent mix for you. Bred koi hatch with mixed parent patterns. You can choose the parent mix, such as 65% one parent and 35% the other, and bred koi can carry several koi lines forward. They start small, save with your aquarium, and grow into more space. Premium Koi Growth Food is a pricey koi-only item that speeds up koi growth, but bigger koi may need bigger koi tanks.

Pause And Music

Pause stops earning and fish care changes until you resume. Music can be turned on or off from the top of the game.

Leaderboard

Add Current Aquarium puts your current normal aquarium on the live leaderboard with its aquarium name, leaderboard name, coins, fish count, koi count, and score points. The score uses your coin points, regular fish rank points, koi rarity points, tank points, and current streak. The streak number means how many questions you answered correctly in a row. More expensive koi are worth more rarity points, and bred koi can score from their parent lines. Remove Published takes it off again. The local test room cannot publish because it uses testing coins.