The river of life flows from the crystals
Near the tree of life
These Crystals purify the water
So that it would extend the life of an elf
Heal a wounded or sick elf if they cannot heal themselves
They also enhance the psychicness of the elves

With the energy of the crystals + the wonderfull fun playfullness of the elvee's company + the minerals from the mud they play in, and the essence and scent from surrounding plants
This is the ultimate therapy an elf can have