What kind of water can be used in irons and in ironings systems?

Our ironing systems have to be used with tap water.In case of very hard water (hardness above 27 ° F) we suggest using demineralised water (unscented) diluted to 50% in tap water. Never use chemicals or cleasing solutions (eg. scented water, essences, descaling solutions, etc.), mineral waters or other kinds of water (eg. rain water, water batteries, dehumidifiers).