Beautiful goldfish 

only anubias, amazon thin leaf is still eaten. I have grown some anubias types successfully in 400 litres ponds, my goldfish are above 18 cm and they can not chew these plant's leave. Anubias develop bigger and stronger.

You could also try java fern. Most goldfish don’t like the texture of it

You can feed them wide varieties of food including pellets, blood worms, gel food, some veggies & fruits as well.

live bloodworms or daphnia are great!

Green pease also will do. It will help your fishes have a better digestive system. It will prevent SBD

All goldfish eat plants

MAN GOLD .. shut up. I’m too lazy to type Chinese right now, but F off, bOI