Zest 3 of the lemons. Place the lemon zest in a small saucepan with 2 cups of the water.
Stir and bring to a simmer but don't boil you just want to dissolve the sugar and get the lemon zest flavor into the liquid. Reduce the heat to low and let the mixture steep.
Juice the remaining lemons and the 3 you zested. I pour the juice through a fine mesh strainer straight into the pitcher because i completely hate some pulp. This step is not necessary it's all about preference.
Pour the simple syrup you made with the lemon zest into the pitcher with the lemon juice. I also pour this through a fine mesh strainer to remove the zest but again its prefrencably,
Stir. Add the remaining 6 cups of water. Taste. Add more water if it is too sweet or tart. Pour over ice and serve immediately or let it chill and serve later.