Sun water is made by placing clean water in a clear glass container and leaving it in direct sunlight for several hours, typically between 3 and 6 hours. The practice has roots in various spiritual and wellness traditions, where practitioners believe sunlight “charges” the water with energy. While the science behind energetic charging is unproven, sunlight does measurably change water’s properties, and there are real safety considerations worth knowing before you start.
What You Need
The container matters more than anything else. Use a clear glass bottle or jar with a lid. Glass is chemically stable in heat and sunlight, which is why laboratories use glass media bottles for light-exposure experiments. Mason jars, clear glass water bottles, and glass carafes all work well. Avoid colored glass if your goal is full-spectrum sun exposure, since tinted glass filters out portions of the light.
Do not use plastic bottles. When plastic (especially PET, the type most water bottles are made from) sits in direct sunlight, chemicals called phthalates migrate into the water. These are endocrine-disrupting compounds, meaning they can interfere with your hormones. Research published in Science of The Total Environment found that sunlight exposure significantly increased phthalate levels in PET bottles compared to bottles stored in shade (with statistical significance at P < 0.001). Higher temperatures and longer exposure made the problem worse. Glass eliminates this risk entirely.
For the water itself, use filtered, distilled, or spring water. Tap water works too, as long as it’s safe to drink from the start. Sun water is not a purification method for questionable water sources (that’s a different process with different rules).
Step by Step Process
Fill your clean glass container with water, leaving a small gap at the top. Seal it with a lid to keep out insects, debris, and airborne bacteria. Place the container outdoors in direct sunlight, ideally on a light or reflective surface like a white table or a sheet of aluminum foil, which bounces additional light into the bottle from below.
Leave the water in the sun for 3 to 6 hours. Most practitioners aim for a minimum of 3 hours on a bright, clear day. If it’s partly cloudy, lean toward the full 6 hours. A sunny morning-to-afternoon window works well. Some people time their sun water to coincide with specific events like solstices or particular moon phases, but the basic method stays the same regardless.
Once your time is up, bring the water inside and let it cool to room temperature before drinking or storing it.
What Sunlight Actually Does to Water
Sunlight does interact with water at a molecular level, though not in the mystical way some wellness sources describe. Ultraviolet light at around 270 nanometers (in the UVC range) increases the electrical potential of water at surfaces, making it more negative. Researchers have proposed that this absorbed UV energy may enhance the formation of structured water zones and could be linked to increased movement of electrons between water molecules. These are real, measurable physical changes.
Sunlight is also remarkably effective at killing bacteria. Research on E. coli in water found that bacterial counts in transparent containers dropped by at least 90% compared to dark containers over the course of a sunny day, with most inactivation happening by late morning. The two main mechanisms are direct DNA damage from UV light and oxidation of bacterial cell components. The World Health Organization endorses a method called SODIS (solar water disinfection) that uses this principle: clear water in clear bottles, 6 hours of sun on a bright day, produces water safe to drink. Water temperature during solar exposure typically reaches 30 to 50°C, which adds a thermal kill effect above 30°C for common bacteria.
None of this confirms the spiritual or energetic claims made about sun water. But it does mean the water you pull out of the sun is physically different from the water you put in.
How to Store Sun Water
Store your sun water in a sealed glass container in a cool, dark place. A pantry or cupboard at roughly 50 to 70°F is ideal. Keeping it out of further sunlight preserves whatever properties the initial charging created and prevents any slow degradation if you’ve transferred it to a different container.
Use or replace your sun water within a few days. Unlike commercially sealed bottled water, homemade sun water has no preservatives and sits in a non-sterile environment. If you’ve used tap or spring water rather than distilled, microbial growth becomes more likely over time. A conservative guideline from New Mexico State University recommends replacing any non-store-bought stored water every 6 months at most, but that applies to sealed emergency water kept in ideal conditions. For sun water stored at room temperature in a jar you’ve been opening, 2 to 3 days is a more reasonable window.
Common Additions and Variations
Many people add elements to their sun water for personal or spiritual reasons. Crystals are popular, but some are genuinely dangerous in water. Malachite contains copper, pyrite can release sulfur compounds, and selenite dissolves. If you want to include crystals, place them outside the jar rather than submerged, or use only stones confirmed as water-safe (clear quartz and amethyst are commonly cited as stable options).
Herbs, citrus slices, or flower petals are other common additions. These turn sun water into more of an infusion. Keep in mind that adding organic material shortens shelf life considerably, since plant matter provides nutrients for bacteria. Drink herbal sun water the same day you make it.
Some practitioners make moon water using the same method under moonlight. The process is identical, though moonlight delivers far less UV radiation, so the measurable physical and germicidal effects of sunlight won’t apply in the same way.
Safety Considerations
The biggest risk with sun water is using the wrong container. Stick with glass. Even food-grade plastic that seems sturdy will leach chemicals when heated by the sun, and the effect compounds with reuse.
Start with water you already know is safe to drink. Solar exposure does kill many common bacteria, but it’s not reliable against all pathogens, especially in turbid or cloudy water. The WHO’s SODIS guidelines specify water should have low turbidity (less than 30 NTU, meaning it looks clear) for solar disinfection to work. If you can’t see through the water clearly, sunlight won’t penetrate deeply enough to do its job.
Don’t leave sun water sitting at warm temperatures for days after making it. Bacteria that survive the initial sun exposure, or that enter the water when you open the container, can multiply in warm, still water. Refrigeration slows this significantly if you plan to keep it longer than a day.