Purifying Water with Light

I'm considering a Steripen water purifier which uses ultraviolet (UV) light to render the genetic material of pathogenic viruses, bacteria, and protozoa incapable of reproduction, and therefore harmless. Right now I use chlorine tablets or filter or just drink water untreated and unfiltered.

Photo by SteriPEN

A few disadvantages of filters which might not be obvious:

• They weigh more than specified because they retain water.
• They can stop filtering and allow pathogens to pass through without any indication of failure. This could occur due to a drop or freezing.
• They can clog. Most can be flushed, but that requires clean water.

Obviously a Steripen is an electronic device which could fail without warning or due to being dropped or a battery failure. Also, it doesn't remove or deactivate multicellular organisms or their eggs. Don't rely on it where tapeworm eggs or similar pathogens are likely to be an issue.


Other advantages of using a Steripen I like:

• No change in taste like when using purification chemicals.
• Works on protozoa, which chemicals struggle with.
• Works on viruses, which few filters effectively remove.