A 10 gallon is too small, listen to Ed. Many years ago many things weren't understood about fish, and fish were kept in more cramped quarters. Much of this had to do with the cost of aquariums, with slate bases & metal frames. Economics caused customers to buy smaller tanks, and fish to be kept & bred in these smaller tanks. Many fish commonly bred today were rarely bred 50 years ago, sufficient tank space has helped this progression.
After 10 gallons the most commonly sold tanks today are 55 gallons. Years ago a 55 gallon or larger tank was very rare, and costly.