Diet lemonade

I'm tired of diet coke. I couldn't find a good recipe for diet lemonade so I came up with my own and it's very nice.
3 lemons squeezed = 1/2 cup
1 1/2 cup water (I use cold mineral water )
1 tsp of sacharine or non sugar sweetener
Just mix and it's done. You might need to add more sweetener because not all lemons are equal nor are some of my teaspoons!