The only drawback to these units is that they use more water than is actually purified, so some is wasted and lost down the drain. This is a consideration in water-scarce areas. Ozone gas purifiers are extremely effective and leave no residual chemicals in the water. Many municipal water plants now treat all their water with ozone gas. In addition to killing bacteria, cysts, and virus, it improves the taste.
Ozone quickly dissipates from the water, so there is no harmful health effects from it.
UV purifiers pass an intense light beam through the flow of water inside the unit. Small portable ozone purifiers are also ideal for camping or during emergencies. Hang the tube and bubbler stone into a jug of water and switch it on. Another good use is to purify and clean fresh fruits and vegetables. Fill your sink with water.