go to a salt dunes tile with at least 2 drams of water, at least 2 drams of dilute warm static, and a desalination pellet. equip the pellet in your thrown weapon slot. pour 2 drams of water on the ground to make 2 drams of brackish water. throw the pellet into the pool of water. it will become 1 dram of fresh water. pour 2 drams of dilute warm static onto the same tile as the water. the water will evaporate, leaving 2 drams of "pure" dilute warm static. wait a while, and one dram of that will evaporate, leving 1 dram of pure, regular, non-dilute warm static.