Food & feeders

How much koi eat

Koi are cold-blooded. Their appetite follows the water: nothing below 8°C, full at 24°C, and a little more in a heatwave.

food a day = weight × % × appetite × portion

• Fry in the fry pond eat about % of their weight a day, the way real fry do.
• In the cold the koi stop eating and don’t need food, so winter never starves them. They only go hungry when they want food and the feeder is empty.
• Hungry koi stop growing at once, weaken after 3 days, and only then start to die.
• High ammonia puts koi off their food: above 0.5 mg/L they eat less, down to a third.

The foods

Every food is a row of properties. Ammonia and solids are what each kilogram eaten puts in the water.

Wheatgerm is the cold-water food: easy to digest, so it fouls the least, just when the bacteria are too cold to keep up. Growth food grows koi fastest but makes the most ammonia.

Portions

Each pond has a portion setting in the Care tab:

• Koi eat up to % of their appetite if it’s there. A Heavy portion grows them a little faster; what they can’t eat sinks and rots.
• Growth follows how much of their appetite they got, to the power 0.6: a Light portion costs about a quarter of the growth for 40% less waste.
• A Light portion is the quickest fix for a pond whose bacteria can’t keep up.

Feeders

The feeder holds kilograms. Filling it costs the food that’s missing. A plain hopper keeps dropping at least % of a summer portion even when the koi stop eating, so in autumn some food rots. The timer feeder matches every feed to the appetite.

The Care tab shows how many days the feeder lasts at today’s appetite. Upgrade it in the Upgrades tab; the food already in it moves across.

What feeding costs

Basic pellets cost a kilogram; other foods cost a multiple of that.

Per day in summer on basic pellets, Normal portion.