Tetra

How many fish can I keep?4 min read

Why "one cm of fish per liter" falls short, and what adult size, schools, territory and swimming zones mean for how many fish a tank can hold.

How to set up a South American aquarium4 min read

Soft, acidic water, subdued light, sand, roots and fallen leaves: how to set up a biotope aquarium from the Amazon and the rivers around it.

How to add new fish4 min read

From the store to the tank: how to get the fish used to your water, why you should add only a few at a time, and what to watch for in the first few days.

Quarantine for new fish3 min read

Why new fish should live in a tank of their own for a few weeks before they move in, what you need, and what to look for.