Fuel for Fusion
Fusion uses two isotopes of Hydrogen called Deuterium and Tritium. Deuterium can be made from water, by a process called electrolysis. It basically means that an electric current is passed through water. This splits the water into Hydrogen and Oxygen. Since Deuterium doesn't conduct electricity the leftover water after electrolysis has a high concentration of Deuterium. Tritium can be made from shooting neutrons at Lithium or Deuterium. In the case of Lithium, when neutrons are shot at it it breaks into two atoms of Helium and one atom of Tritium. In the case of Deuterium, when the neutrons are shot at it the Deuterium absorbs the neutron to form Tritium.