Pond Flakes are a great food for smaller pond fish. A good quality pond flake will have all of the nutrients that these smaller fish require to thrive and grow, but in a size that they can easily consume. Finely crumbled pond flakes are a perfect diet for fry, though you may need to feed them in a position where the bigger fish cannot take all of the food.
Pond flakes are not ideal for larger fish (over15cm in length). Such fish will still eat the larger flakes, but will tend to ignore the very fine particles of flakes, which will then sink to the pond bottom and start to decompose. For these fish pond sticks are a better option, as they are in bite-sized pieces.