Add to your blender:
1 handful (or more) of any green leafy vegetables (for example: parsley, spinach, kale, swiss chard, dark leaf lettuce, beet tops, mustard greens etc.
Several stalks of celery
Enough purified water to blend
Lemon juice (optional)
Blend well. Add mixture to a 2 quart or 1 gallon pitcher (strain if desired). Add enough additional water to fill pitcher. Drink and enjoy. Refrigerate unused portion. Should be made fresh every 24 hours.