Small tanks are really difficult to manage. It’s possible to grow coral in a 1-2 gallon tank but it’s extremely difficult most people fail eventually. 5 gallon

Small tanks are really difficult to manage. It’s possible to grow coral in a 1-2 gallon tank but it’s extremely difficult most people fail eventually. 5 gallons is like the minimum for a few small fish but 40-45 gallons is a really easy size to work with. Overfeeding, evaporation and overheating are going to be your top problems in small tanks.