As with most other freshwater shrimp you don't need a large aquarium to keep crystal blacks. Keep in mind that they are quite sensitive and don't react well to bad water values, which means a larger aquarium is better especially if you're a beginner. An aquarium of at least 10 gallons is easier to keep stable than smaller setups.
Like all aquariums a crystal black shrimp tank should be fully cycled and established before any inhabitants are introduced. You need a filter to cycle the tank; most shrimp breeders prefer sponge filters, as these create a gentle water flow and can't suck up tiny shrimp fry. Although crystal black shrimp can handle room temperatures just fine it's still recommended to use a heater to prevent any temperature fluctuations.
Crystal black shrimp love plenty of hiding places in the aquarium, especially when they're vulnerable during molting time. Shrimp flats and live plants make great hides while also providing a place for nutritious biofilm to grow, so be sure to incorporate a few in your crystal black tank.