Add water and salt to a pot and bring to a rolling boil. Remove from heat, then stir in Mānuka Honey until dissolved. Pour this into a large bowl and add the apple cider vinegar.
Either in a metal strainer or by hand, add the sliced fruit to the tonic and let everything sit for at least one hour. Before removing the fruit, mash with a fork to extract as much flavour as possible. Strain out the soaked fruit, pour into a jug and chill overnight.
To serve, add ½ cup sparkling water to a glass over ice followed by 1/3 cup tonic. Serve with herbs and fresh fruit as garnish.