Baking soda neutralizes the ph in the soil and nothing will grow there. use baking soda around all of the edges of flower beds to keep the grass and weeds from growing into beds. Just sprinkle it onto the soil so that it covers it lightly. Do this twice a year - spring and fall.
water feature has a "fall rock" set atop some other rocks to create a cave; like cupping your hands to holler a long distance, this amplifies & aims the sound of the falling water towards a sitting area -- easy water gardens