At last! someone else who teaches their fish their names. I did this when I started feeding peas to my first pond fish when they were just babies. They varied a lot in size, so I made them take the peas from my hand so everyone was fed. I'd call a name and put the pea in front of the named fish's mouth. Within a week, some of the fish would come to my hand with their mouths open when they heard their name (some smacking loudly). Some were wilder, and wouldn't come at all. When such a fish would grab a pea, I would say its name. It was easy to tell these shy fish learned their names. They would become highly agitated when I called them; would try to approach my hand, then lose their nerve and dive for the bottom. Marcin Goldfish couldn't get himself to take food from my hand for a full year. Now he takes food from my hand with great confidence, but unlike some of the fish who hang around close while the other fish are fed, he doesn't come near me until I call him.
Wildeye has never been fearful, but she waits quietly until I call her. Some of the fish like to take food from my hand so much that if I throw food in the pond, they would just stay watching me, waiting for me to feed them. So I taught a new command: "Find it!" I say this when I toss food in the pool. Within a few days, all of the fish would look for food on the pond surface when I said this.
When I add a new fish to a pond in which the fish all hand feed when their names are called, the new fish picks it up really quickly. Goldfish pay great attention to how other goldfish get food. Learning really accelerates when they are learning from their pondmates as well as me. Learning their name in 2 days is not unusual.
It's not hard to tell that a fish recognizes its name when it's swimming away, you call it, and it makes a u-turn and sticks its mouth out of the water.
I will try this, the only problem I might have with it is both their names sound kinda similar, Saffy and Sandy, will see how I go