The next time some youngster asks you what adulting is like, put it this way: “Suddenly, you’re concerned your water filter is either dirty, the wrong one, or needs to be replaced, but you can’t remember where you put the book that tells you how to do it. You can’t remember where you put the replacement water filters, either, so you hit the reset button and figure you’ll just worry about it again in a few months.”
Chances are good that most people have a water filter of some kind in their home, but these seemingly simple devices — they just filter water, right? — are surprisingly complex. There’s a lot of legitimate questions that come with water filters, and given the fact that it’s a matter of keeping your whole family healthy, you really should ask them. Do you really need to use a water filter? Are they worth the insane amount of money they cost? Do you really, really need to replace them? Are they really making your water safer to drink?
Don’t worry — we have the answers. This is the truth about water filters.
Water filters are way older than you’d think
Here’s a fun bit of trivia — water filters aren’t a modern invention.
According to Lenntech Water Treatment Solutions, the basics of water purification go back to 2,000 BC.
Records from ancient Greece, Egypt, and India show that they knew how important clean water was, and it was boiled and filtered, usually through sand or gravel. In 500 BC, Hippocrates developed something we’d recognize as a water filter. He called it the Hippocratic sleeve, and it was essentially a cloth bag he’d pour water through in order to strain out sediment.
While Rome had built a massive system of aqueducts and infrastructure, the fall of Rome destroyed much of that and put a lot of things on hold. It wasn’t until 1627 that Sir Francis Bacon tried straining salt from water through sand.
By the 1700s, some homes were using filters made from sponge, charcoal, and wool, and filtration wasn’t done on a municipal scale until Scotland built the first water treatment plant in 1804. In 1854, a cholera epidemic swept through London and we discovered that even though water might look safe to drink, it wasn’t necessarily clean.
Water Filters Australia says it was Queen Victoria who really increased the popularity of home water filters, specifically in the form of pottery crafted by Royal Doulton. Carbon filters came along in 1862, and all that was left was to perfect the idea that people had been working on for centuries.
Most water filters have a physical and a chemical component
There are a few different kinds of filters, but most work on the same general principle. According to Explain That Stuff, most filters have two parts that work together to remove impurities from the water. First, there’s a physical part — which is where the water is strained through something like a fine mesh — and that usually takes care of the larger impurities.\
The other method is chemical filtration, and at a glance, this sounds pretty similar. Here, though, the water passes through something — like activated carbon — where there’s a chemical reaction that causes the impurities to be pulled from the water and into the filter.
Activated carbon filters are the most common when it comes to household use, says Frigidaire. That’s because it’s sort of the best of both worlds. Larger particles get caught on the surface of the charcoal, and the carbon absorbs some of the other contaminants you don’t want in your water, particularly lead and volatile organic compounds, or VOCs. Then, there’s a chemical reaction happening here, too, and it’s that reaction that helps get rid of the chlorine in the water.