Water is so important
When brewing a tea, water is the most important element, after selecting a quality tea.
If you use the tap water and your tea would taste terrible in the most part of the world. The bottled water, either spring water or distilled water is much better. You could consider to buy a water filter to improve the quality of the tap water.
For green teas, don't use boiling water or you would cook the tea. One way to do it is that firstly pull barely enough water to cover the tea leaves, let it cool down a bit. Once you are ready to drink, pull warm water to fill the cup and serve.
Be sure to wash a Pu-erh tea before anything else. Use boiling water, but try different infusing time, from 10 sec. to 30 sec. to gain the best result.