The Dark Elixir Storage is a transparent, rectangular-shaped building. It is stated that this storage had to resemble a cube due to the Dark Elixir's power.
Upgrading your Dark Elixir Storage to a higher level than you require for storage purposes can potentially save Dark Elixir in a raid. As an attacker receives an amount of Dark Elixir proportional to the percentage of damage each hit causes, the higher health of the upgraded building results in less Dark Elixir per hit. It also takes longer to destroy, giving you more time for your defenses to destroy the attacker before they can steal all the available Elixir
The Dark Elixir Storage building takes up a 3x3 space.
Dark Elixir Storages remain fully functional while being upgraded, like all other Storages.
Some people deliberately avoid getting the drill and just get the storage because it is much faster to raid for Dark Elixir than it is to collect it on your own.
If a player without a Dark Elixir storage raids Dark Elixir, the looted Dark Elixir will not be stored and will simply disappear. It will, however, give credit toward the Heroic Heist achievement.
Due to the low cap on Dark Elixir, it is sometimes difficult to tell if the Dark Elixir Storage is full; a level 6 Dark Elixir Storage with just under 40,000 Dark Elixir (almost enough to reach the 2,000 cap) is less than 20% full and therefore appears empty.
Dark Elixir is the most difficult resource to obtain, with the possible exception of Gems.
The Dark Elixir Storage is unlocked at Town Hall level 7, along with the Dark Elixir Drill.
Upgrade Differences
Dark Elixir Storages undergo mostly minor visual changes as it is upgraded. The two significant changes occur at levels 3 and 5.
When initially constructed, the Dark Elixir Storage consists of a transparent, slightly rounded cubical storage vessel situated on a four-legged wooden platform. There appears to be a small square opening at the top of the storage.
At level 2, the Storage adds a brass frame to the top of the vessel and a metal spigot at the base.
At level 3, the Storage grows substantially in size, and both the wooden platform and brass frame are replaced by versions made of steel.
At level 4, the Storage gains dark gold legs and a bigger and slightly different tap.
At level 5, the Storage receives spiked steel armor plating on each of the four corners of the base.
At level 6, these armor plates become slightly wider with a pair of small golden spikes on each, and the steel frame atop the vessel turns golden as well.
Trivia
Although the description refers the Dark Elixir as "three times as powerful", in the game it is in fact 100 times as powerful. This is observed by two facts: for example, both 1,000,000 Elixir and 10,000 Dark Elixir can be bought with 600 gems; the loading costs of a level 1 X-Bow is 50,000 Elixir, while the level 1 Inferno Tower consumes 500 Dark Elixir.
Upgrading your Dark Elixir Storage to a higher level than you require for storage purposes can potentially save Dark Elixir in a raid. As an attacker receives an amount of Dark Elixir proportional to the percentage of damage each hit causes, the higher health of the upgraded building results in less Dark Elixir per hit. It also takes longer to destroy, giving you more time for your defenses to destroy the attacker before they can steal all the available Elixir.
