The best foods to make a goldfish grow is just a good variety of foods.
An example, I have two ryukin fry in a 66 gallon. They have doubled in size since I got them a little over a month ago.
I am feeding
Frozen brine shrimp
Frozen blood worms
Frozen goldfish food...which contains spiralina,bloodworms, veggies, and krill
Hikari goldfish pellets for orandas
another kind of pellets...can't remember the name
flakes...a variety
shrimp pellets
Hikari algae wafers.

If I could find the hikari wheat germ pellets, I would add them also.....but there is no chance of finding them around here.

Keep the water very clean and your goldfish will grow and flourish.

Goldfish do grow slow.

Good luck,
Sierra

Many thanks, Sierra, for your great help! Do you feed your 2 fish with all the food mentioned in your post once every day? Will there be an overfeed problem? How many times a day do you feed your fish? I heard that beefheart is good for goldfish growing big as well, what do you think? It seems my fish hates the flavor of frozen beefheart, everytime I put the frozen beefheart into the tank, I just see her swim over it as if there was no food there.

Hi,

I choose only one food a day and only feed once a day. I let them eat for hmmmm, I don't really time them, but I would say it ranges between 10 minutes and 20 minutes. I remove any un-eaten food, if I happen to over feed.

Beefheart is a good fish food, but many fish don't like. I don't feed that to my goldfish. I used to feed beefheart to the discus.

The frozen foods mentioned above come in little squares....I thaw a square.....but its too much food for two little ryukins, so I don't usually give it all to them.......If I forget and dump it in, I clean out the un-eaten portion.

Your fish will grow as long as they are healthy.

Sierra

thanks i will try that hopes it works *fingers crossed*