Putting goldfish fry in the pond -- size or age parameters?
I am raising some of my Goldfish fry inside.
At what point is it best (safest for the continued survival of the babies) to add them back into the pond? The biggest now are around an inch long.
Size is the most important parameter.
The way goldfish fry are raised has a huge impact on their size at any given age, but the dangers fry face change as their size increases.
When you describe your fish as around an inch long, I am assuming that is body length, not total length.
If their body length is less than one inch, there are still too many insect enemies that can kill them.
I have made a list of the more common fry enemies
At an inch long, all the natural water borne insect enemies of fry are too small to bother them, however, they are now an ideal size for birds, frogs, newts and salamanders.
For this reason I always recommend a pond cover as it greatly increases the odds of survival for small fish.
Goldfish are fairly social, and don't tend to chew on each other, but any large fish in the pond say over 5 inches in body length could try and fit a small fish in its mouth.
Provide some hiding spots for the fry if large fish are present.
One last consideration if there are adult fish in the pond is parasites.
Goldfish less than two inches in body length are susceptible to flukes, especially if the pond is heavily stocked.