Press the base of the bottle and a ring of light climbs up through the water. It runs for sixty seconds and switches itself off. Here is what is happening, in plain words.
What UV-C is
Sunlight carries ultraviolet light in several bands. UV-C is the shortest, and almost none of it reaches the ground. At 275 nanometres it is absorbed by the genetic material of microbes, which stops them from multiplying. Water treatment plants use ultraviolet light for the same job.
What the base does
The base holds a ring of UV-C LEDs that point up into the water. Press it and the ring lights for a sixty-second cycle. In auto mode it runs a cycle every four hours on its own, so water that sits in a bag all day still gets a fresh pass.
- Wavelength
- 275 nm
- Cycle
- 60 s
- Auto mode
- Every 4 hours
- Battery
- 40 cycles per charge, USB-C
A full charge takes about ninety minutes over USB-C. When the ring blinks twice, it wants charging.
What it doesn't do
Light is not a filter. It doesn't take out grit, metals or chemicals, and it doesn't change the taste or the minerals in the water. Fill the bottle with water you would drink anyway, and let the light look after it while you carry it.
Why you only see a glow
UV-C isn't something to look into, so the ring points up into the water and the sleeve covers the base. From the outside you see a soft violet light in the glass, and that's all.
