Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to care for a zebra danio [title] Purchase a ten-gallon tank or larger. [step] 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.

Ending1: You should also have enough space inside the tank for your dog. [substeps] Danios require plenty of room to move around, but a 20 gallon tank can provide at least 24 gallons (75.7 l) of space. Ending2: [title] Give your danios plenty of room to explore on a land surface. [step] 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. Ending3: [substeps] Danios also need good bodies of water for swimming. You can find a cold water tank at your local pet store. Ending4: [substeps] 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.

Answer format: ending1/ending2/ending3/ending4