What is the correct number of fish for a tank?

There is no single "correct" number of fish for a tank, as it depends on several factors such as the tank size, the fish species, and the filtration system. However, as a general guideline, it's recommended to start with 1 inch of fish per gallon of water. This means that if you have a 10-gallon tank, you could start with 10 one-inch fish. However, it's important to keep in mind that some fish species grow larger than others, so it's important to do your research and choose fish that are appropriate for the size of your tank. Additionally, it's always best to consult with an experienced aquarist or aquatic specialist to determine the ideal stocking level for your specific tank setup.