Feed koi a high-quality pellet food as their staple diet, and let water temperature — not the calendar — decide how much and how often. Above 15 °C, koi digest protein-rich food readily and can be fed once or twice daily; between 10 and 15 °C their metabolism slows and feeding drops to a few times a week; below 10 °C, stop feeding entirely until spring. In Canada, that last rule matters more than anywhere else — feeding too late into a cold fall is one of the most common causes of overwinter koi losses, because food sits undigested in a fish whose gut has effectively shut down.
The staple: quality pellets
A balanced pellet formulated for pond fish should make up the bulk of every koi's diet. Aquascape Premium Staple Fish Food Pellets are formulated for everyday feeding and cover the protein, fats, vitamins and minerals koi need through the growing season. For smaller koi and goldfish that struggle with full-size pellets, Aquascape Premium Fish Food Flakes do the same job in an easier bite.
Treats and hand feeding
Part of the joy of keeping koi is that they learn to greet you. Aquascape Koi Krunchies are made for exactly this — a nutritious supplement for hand feeding koi, goldfish and other pond fish, fed a few pieces at a time rather than by the handful. Occasional extras from the kitchen are fine too: koi will happily take small pieces of orange, watermelon, lettuce, spinach and peas (shelled). Skip bread entirely — it offers no nutrition, swells in the gut, and the leftovers degrade water quality.
How much and how often
Follow the five-minute rule: feed only what your koi finish completely within about five minutes, once or twice a day in warm water. Uneaten food is the enemy — it decomposes into ammonia and phosphates, clouding water and feeding algae. If food is left floating after five minutes, you fed too much; net it out and reduce the next portion.
The Canadian feeding calendar
Spring (water 10–15 °C): resume feeding lightly, two to three times a week, with an easily digested food. Koi come out of winter with depleted reserves but a still-sluggish metabolism — patience here pays off.
Summer (above 15 °C): full feeding, once or twice daily by the five-minute rule. This is the growth season.
Fall (dropping through 15 °C toward 10 °C): taper frequency as the water cools. Use a pond thermometer rather than guessing — Canadian falls can swing 10 degrees in a week.
Below 10 °C through winter: stop feeding completely. Koi enter torpor and live off reserves. They will sometimes mouth at the surface on a mild day — don't be tempted. Feeding resumes only when water holds above 10 °C in spring.
Feeding is only half the picture
Everything a koi eats ends up in the water, which is why feeding and water quality are the same conversation. Keep aeration running through the season so oxygen stays high, use Ammonia Neutralizer if levels spike after heavy feeding, run adequate pond filtration, and keep an opening in winter ice with a de-icer or aeration so gases can escape while your koi overwinter below. If green water develops during the summer feeding season, a UV clarifier clears it without chemicals.
Frequently asked questions
What should I feed my koi every day?
A quality staple pellet sized to your fish, fed by the five-minute rule once or twice daily in warm water. Flakes suit smaller fish; treats like Koi Krunchies are supplements, not the base diet.
Can koi eat bread?
No. Bread has no nutritional value for koi, can swell in the digestive tract, and the leftovers pollute the pond. Offer shelled peas, lettuce, or small fruit pieces instead.
When should I stop feeding koi in Canada?
When water temperature drops below 10 °C and stays there — typically mid-to-late October in southern Ontario, earlier further north. Trust a pond thermometer, not the air temperature.
Do koi eat algae?
Koi graze on soft algae and plant matter, and it's a natural part of their diet — but grazing won't control an algae problem. That takes nutrient management and aeration; see our algae-control collection.
How long can koi go without food?
In cold water, all winter — that's exactly what they do under the ice in Canada. In warm summer water, healthy koi in an established pond with natural forage can go a week or two without supplemental feeding, such as during a vacation.
Questions about feeding, water quality, or overwintering koi in your pond? Email Info@fountaindepot.com or call 905-752-1226 — advice backed by 50+ years of pond and fountain service in the GTA. Fish food and pond care products ship across Canada from Markham, Ontario.
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July 17, 2026
July 17, 2026