Zebra Danio

A shoal of at least six needs a minimum of about 60 litres, and a long tank is far better than a tall one because danios are tireless swimmers that use every centimetre of horizontal space. Plant the sides and back and leave a long open swimming channel down the middle. Fit a lid, as these active fish are capable jumpers, especially when startled or during feeding.

Zebra danios are omnivorous micro predators, so feed a good quality flake or micro pellet as the staple, plus frozen or live daphnia, baby brine shrimp and micro bloodworm for variety. Offer a small pinch once or twice a day that they finish quickly, since these fast eaters are easy to overfeed.

One of their great strengths is tolerance of cooler water, so keep them at about 18 to 24 degrees Celsius, cooler than most tropical fish and sometimes kept without a heater in a warm room. They accept a wide pH range of about 6.5 to 7.5 and soft to moderately hard water. The tank must still be cycled with ammonia at 0 and nitrite at 0 and nitrate low. Dechlorinate tap water and change about 25 percent weekly.

Zebra danios are true schooling fish and must be kept in groups of at least six, and ideally eight to ten or more, because in small numbers they become stressed and turn to nipping fins, with one fish often relentlessly chased. In a proper shoal they are peaceful and outgoing, though their speed and energy can bother slow or long finned tankmates, so choose robust companions.

A long open swimming lane is the most important feature, letting the shoal race and turn together, with plants at the sides for cover and a gentle current they enjoy playing in. Their constant activity is itself part of their charm, and a larger group behaves more naturally and confidently.