Your Philips Steam Cleaner is designed to be used with tap water. If you live in an area with hard water, rapid scale build-up may occur. In that case, use distilled water and replace the descaling filter every 6 months to prolong the life of your appliance.
For optimal cleaning results, use distilled water. Do not put detergents, perfume, vinegar, starch, descaling agents, ironing aids or other chemicals in the water tank, as your appliance is not designed to work with these chemicals.