How many fish can I put in a 40-gallon tank?
One of the most common but hardest questions we get is “How many fish can you put in a 40-gallon aquarium? What about a 20-gallon tank? 55 gallons?” As you may guess, there is an infinite number of possible fish combinations for each tank size that we could recommend. To simplify things, read this article that discusses the three factors that will most impact your fish stocking levels, as well as our general guidelines for introducing the right number of fish to your aquarium.