* Species: Different fish species have vastly different growth rates. A goldfish might take a few years to reach full size, while a tuna could be full grown in a few years.
* Environment: Factors like water temperature, food availability, and the presence of predators all influence how fast a fish grows.
* Genetics: Individual fish within a species can have different growth rates based on their genes.
* Sex: In some species, females grow larger than males.
Here are some examples to give you an idea:
* Goldfish: 1-3 years
* Koi: 5-10 years
* Guppies: 6-12 months
* Salmon: 2-5 years
* Tuna: 3-5 years
It's important to remember that these are just general estimates. To get a more precise idea of how long a particular fish will take to grow, you can consult a fish care guide or talk to a fish expert.