Live foods are in demand by Fish hobbyist, being a natural food, they have high nutritional value and they also have the advantage that any live foods left uneaten will survive and will not pollute your pond.Some of the live food suitable for koi or goldfish can contain parasitic or disease forming organisms. Anything in your backyard should be safe for your aquarium as your fish in the pond are already eating it. Breeding your own live foods if you have time is great as well, however live food is totally dependent on the weather and seasons, so its not that easy to sustain a reliable source.You should always be feeding processed foods for goldfish and koi fish as well, to give the captive fish the nutrients and minerals they need. 

You can also find food in your garden, today i came across a potted plant that had tiny little aphids on it, I shook the plant over a pond and wiped all the leaves free of bugs & the fish had a feast

Earthworms for your koi and goldfish. You can collect them from the garden, lay a hessian sack in a shady corner of the garden. place a layer of tea leaves underneath it and keep them wet. The worms will accumulate with a steady supply. They are an easily digestible source of live food for fish.

This live food, known as water lice, can be found in both still and moving water. They have a similar appearance to woodlice. fish enjoy eating them, but only fish not fry seem able to crack their outer shell.

Daphnia There are different types, i find daphnia at the end of the winter in the plant ponds, they are very small crustaceans.Then there is another type in the plant ponds that appear in summer. Daphnia swim in a jerky motion and are easy to catch with a Fine Mesh Net, . Established still ponds with lots of plants and no fish will generally have daphnia in them at one point in the year for a few weeks. They are very small, you have to be looking for them to see them. Highly nutritious live food, great for fry. All fish will devour them with relish.

Daphnia hiding under a lily floating leaf in winter

Mosquito Larvae (wrigglers) you see them in any body of water, in summer. You could put a bucket of rain water out in the garden and you will get wrigglers in there, if you move debris from the bottom of any shallow water puddle in summer there will be wrigglers. Wrigglers are black and around 1-2mm, there are several species and the larvae vary in size. Use a fine mesh net to catch them, they will be greedily accepted by all fish.

Glass worms are the larvae of certain types of aquatic insects and can be seen floating horizontally in waterways such as rivers, lakes, and ponds. The way they move consists of quick twists. Typically grow to a size of up to 1 cm and are highly sought after by fish.

Frog eggs spawned in a pond, the fish will eat the eggs enthusiastically, although they appear to ignore those of the toad.

Tubifex worms these aquatic worms are bright red in colour. To avoid introducing disease into the pond, wash worms and thoroughly in clean water for several days to evacuate their intestines.

Blood worms are the larval stages of midges. They swim in a characteristic sideways motion. They provide a nutritious live food.

Plants Duck weed,the algae growing on the side and bottom of your pond & softer plants are food for your fish.

At Windsor fish hatchery we feed some live foods,We dont produce enough of it to feed the hatchery and supply the public. The variety of processed foods that we do sell is essential to the health of any fish kept in captivity. Check out the foods koi fish food, goldfish food