Slice all the emons in half then extract the juice into a jug using either a lemon juicer or squeezing by hand (using a sieve to catch the pips). You should be left with 150-200ml of juice.
Fill a jug up to the 900ml mark with sparkling/soda water.
Slowly add the sugar into the jug (or else it'll fizz over) and stir until the sugar has dissolved into the juice.
Serve over ice with a wedge of lemon and enjoy.