This is because Akasha is all being, everything and nothing, unchanging and forever. It covers everything every where and all the elements come from Akasha, and this has not changed since it was discovered or names. It is used in Buddhism and Hinduism with the translation sometimes being - 'Infinite Source'
Per se' I would not use Akasha in my practice as such, because it is not something you can `use`. However it would always be in my work. Whenever I call upon an element, when I use a spell or ritual that has an element combined, even an elemental meditation. Akasha will always be present.
I know that I got Akasha wrong by thinking that the name was one of a Goddess or maybe even a God. It did not strike me Akasha was the Formal name for Spirit on a Pentagram. There can be many misconceptions on Akasha - Such as Akasha, Vampire queen of the dammed. It also can get confused with Akashic records which are "The Akashic Records or "The Book of Life" can be equated to the universe's super computer system" - Adapted from: Edgar Cayce on the Akashic Records by Kevin J.