How many fishes should you put into a 80 liters aquarium marine?

The number of fish you can put in an 80-liter marine aquarium depends on various factors such as the size and compatibility of the fish species, as well as the filtration capacity of your aquarium. As a general guide, you can follow the "one-inch per gallon" rule, which suggests keeping one inch of fish (measured from snout to tail) for every gallon of water. This means that you could potentially keep around 20 inches of fish in an 80-liter aquarium.

However, it's important to consider the specific needs of the fish you are planning to keep. Some fish species require more space than others, and overcrowding the aquarium can lead to stress, competition for resources, and aggression among the fish. You should also account for the presence of decorations, plants, and other structures in the aquarium, as these will take up space and reduce the available swimming area for the fish.

To ensure the well-being of your fish, it's best to research and select species that are compatible with each other and suitable for the size of your aquarium. It's also a good idea to consult with experienced aquarists or professionals at your local fish store to get personalized advice based on your specific setup and fish choices.