This linguistic confusion is why Americans call the Pennsylvania Dutch Dutch even though they're Germans. To review: this country is the Netherlands, its people are Dutch, they speak Dutch. There is no country called Holland, but there are provinces of North and South Holland.
In clean, uncrowded conditions in tanks or ponds, goldfish grow fast. They can grow to a few inches (1 to 4 inches) within the first year. It really depends on their genetics and living situation. It may take a year or two before they change color from brown to gold or whatever color their parents were.
The best way to get goldfish to grow the fastest is you give them as much room as you can then you give them growth food from the store. You can find it at almost any store that sells fish food. This will ensure that it will grow fast and big. blackheart_21 Â· 7 years ago.