How long does it take for a goldfish to reach adult size?
they don’t really stop growing. They can live for 20 years or more, and their growth pattern is based on food supply and available space, as well as temp–slower at low temps than at warm temps. Here’s some info on lifespan and growth for goldfish. http://www.tropicalfishdata.com/goldfish/goldfish_lifespan.html It is a myth that a goldfish will grow only to the size of their tank. If a goldfish is kept in a small tank, fed only a small amount once daily, and the water changed regularly, it will grow only very slowly and may live for several years, reaching a maximum size of maybe 3 to 4 inches (8 to 10 centimeters). It is true that the growth of a goldfish may be somewhat stunted in a small tank – a high nitrate level is known to stunt growth – but growth is slowed, not stopped altogether. However, if fed too much, or if kept in a tank that is not sufficiently filtered or maintained, a goldfish
