The key to getting delicious tea is choosing the right water. You've gone through the effort of choosing good tea, but the taste can change depending on the water, so let's look at how to get the best water.
It's said that tea made with soft water consisting of a "hardness" of 100mg/L (including magnesium and calcium ion content) makes for good tea. The ideal soft water has a hardness level of 30-80mg/L, which tap water in Japan does have. However, since it's necessary to remove calcium hypochlorite, mineral water is recommended for very choosy people. Also, the ideal ph level is 7-8. If the ph level exceeds 8, the tea will turn a deep green, and if it's less than 6.5, it will become pale. When making tea with mineral water, pay attention to the hardness and ph level.
It's simple to use a water purifier as the smell of calcium hypochlorite will be removed from the water in 4-5 hours, but for those very concerned, it's recommended to take the lid off the kettle when boiling, let the water boil for 3 minutes, and then let it cool at an appropriate temperature. There can be differences depending on the kettle's quality, too. Many use aluminum or stainless steel ones, and these are often enough, but iron kettles are the best. For the very difficult to remove smells, there's a method of putting a handful of the tea's powder and adding a drop of lemon juice, too.