Pastel＊Desert

When you hear the word Oasis, you think of a water spring in the middle of the desert! I imagine that, but in general, it is a lush area in a dry environment. The water comes from various sources such as groundwater, rivers, and melting snow. By the way, I heard that oasis water is difficult to drink with hard water, but I wonder if it's true. I've wanted to try it for a while...