What if we gauged marathoners by how well they ran a 100 meter race? Would that to be a sound predictor for how they would perform over 26 miles? How about a marriage based on the first date? Or what if a movie was given awards based on the first and last 10 minutes only? Nothing in between was viewed.
Would anyone who suggested these ideas be given any credence?
No. But somehow it works when selling water filters.
We continually see people getting sucked into similar thinking, and it then takes a lot of time on our end to point out some considerations. To save all of us some time, we thought we’d make a list of things to be aware of when a filter company shows you their “tests” or a company rep references testing.
- Duration of Tests: In many cases, the filter is used to eliminate a toxin for only a few liters of water. That elimination/reduction performance is then marketed as being consistent over the entire life of the filter. Does that make sense?
- Look in Middle: Another way to stretch performance is to test what’s often referred to as a “witches brew” on the front end for a few liters, then again after a couple hundred or even thousand liters of water is pumped through the filter. No details are given about the majority of water pumped through in between. What if the toxins tested for weren’t in the water for that portion of the test? A filter life can be really long if it doesn’t have to filter.
- Clarification on Certifications: Ask what the certifications mean. Often times, this is more common in the electric ionizer world, a certification is given that has nothing to do with the system itself, but for the factory where it was made. Or it could just be for the electric safety aspect. Not all certifications apply to you how it works in your kitchen
The theme here is that any test needs to match closely to real world every day operation. Better yet, exceed it. If a filter is only going to remove fluoride for 5 liters, or it has all sorts of other caveats, but you plan on pumping 400 liters through it, what good is the test?