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How to care for a zebra danio
Purchase a ten-gallon tank or larger.
Danios are social animals and need space for themselves and their friends. The tank should come equipped with an exterior power filter, a bio-wheel, and an aquarium heater.

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[A]. You should also have enough space inside the tank for your dog. Danios require plenty of room to move around, but a 20 gallon tank can provide at least 24 gallons (75.7 l) of space.
[B]. Give your danios plenty of room to explore on a land surface. Danios generally enjoy basking in the sun by laying in shallow water with their heads on the surface of the water, but they do require low-light environments.
[C]. Danios also need good bodies of water for swimming. You can find a cold water tank at your local pet store.
[D]. Because they are hearty, it is generally possible to keep danios without a heater. However, a heater is good for maintaining optimal conditions, especially if you plan to breed the danios.
[D].