The theertham ideally from a silver or a copper vessel. The water used for theertham usually would contain Thulasi leaves dipped in water and must be stored at least for eight hours in the copper vessel. According to Ayurveda, water stored in a copper vessel has the ability to balance all the three doshas in your body, (vata, kapha and pitta) and it does so by positively charging the water. By drinking this Thulasi water you activate the taste sense. The other benefits of drinking Thulasi water from a copper or silver vessel also includes cure for soar throats, Fever & Common Cold, Coughs, Respiratory Disorder, formation of Kidney Stone, Heart Disorder chances will be reduced
In all the Hindu temples we can see that they provide theertham after you pray the God.