In a small pan, heat 1 cup of water and 1 cup of sugar over medium heat. Stir regularly until the sugar is completely dissolved. Remove the pan from heat and let the mixture cool completely.
Cut the lemons in halves and squeeze lemon juice into a pitcher or other serving glass
Add the remaining 4 cups of water, sugar mixture, and CBD oil, stir well and chill for a few hours.
To serve muddle a few mint or basil leaves in the bottom of a glass. Fill 3/4 of the glass with lemonade, then fill rest of the glass with seltzer water. Add a few mint leaves on top as garnish. ENJOY!