How much money can I save with a water filter?

Almost any health information resource has the same recommendation about water: You should drink about eight glasses (64 ounces) per day [source: Mayo Clinic]. That adds up to 2 gallons per day for a family of four. When your water comes from 12-ounce plastic bottles, the cost can be exorbitant. Let's assume you pay approximately $6 per case of water (and remember, fancy imported waters can be much more), which is equal to $0.40 per bottle. For a family of four, that amounts to an annual cost of:

$0.40 per bottle x 5.3 bottles per person = $2.13 x 4 people = $8.53 x 365 (days in a year) = $3,114.67

Now let's compare that to the cost of using a water filter. There are many different types of water filters, but for simplicity, we'll use the basic pitcher-style system, which retails for about $20 and requires a new filter every 40 gallons [source: Brita]. A family of four will need to replace its water filter 18.25 times per year at a cost of about $6.50 per filter, which amounts to $119. A couple of $12 water bottles for each member of the family will run $96 per year. There is also the cost of water from the tap to consider, which runs about $1.50 per 1,000 gallons in the U.S. A family of four consumes about 730 gallons of water per year (2 gallons/day, 365 days/year), which amounts to $1.10. So, the total cost of using a pitcher-style water filtration system per year for a family of four is:

$119 (filters) + $96 (water bottles) + $20 (pitcher) + $1.10 (water from the tap) = $236.10

That means a family of four can potentially save $3,114.67- $236.10 = $2,878.57 each year by switching from bottled water to a water filter. And when you consider that most tap water is safe to drink in the U.S., you can save an additional $235 per year by skipping bottles and filters entirely, bringing the total annual drinking water cost for a family of four down to just $1.10. However, differences in water may occur when you consider that some municipal supplies do not meet standards of safety and quality, and others may contain foul odors and smells while still testing at safe levels for consumption. In that case, filtering your water is a good idea. Read on to learn about the various types of water filter systems.

Now that you've done the math and determined that you can save a lot of money by giving up bottled water, you still may not be ready to give up the luxury of filtration for your precious H₂0. Understandable -- we all want the safest and best-tasting water available, and filter systems are easy to come by. The good news is that there are lots of different types of water filters, ranging from inexpensive pitchers to futuristic high-tech systems. Let's look at some of the more popular water filtration methods.

By far the most common type of water filters are those based on absorption, most of which use activated carbon. If you recall from high school chemistry, lots of stuff sticks to carbon molecules. When a filter is packed with carbon, particles that pass through bind to the molecules of the filter, trapping contaminants. As time goes on, the carbon becomes saturated with particles and therefore less effective at trapping contaminants, which is why you need to change the filter every so often. This is the basic method of most fridge, faucet, and pitcher filter systems.

There are also many lesser-known yet innovative ways of filtering water. For example, ultraviolet (UV) light can be used to purify water, delivered as a pen or wand that is swirled into a water-filled container for a minute or so. Magnetic fields can also be effective water filters, as can those that work by reverse osmosis or ion exchange. Whatever your water filtration preference, be sure to choose one that captures mercury, lead, arsenic, benzene and microbes. Most filters will come with a list of what is being removed from tap water as well as the concentration of contaminants that may remain. When using a water filter system, it's also important that you choose water bottles that are free of contaminants such as bisphenol A (BPA), a toxic chemical that's been used to make hard plastics since the 1960s.

Your body is about 70 percent water, and these tiny molecules of H₂0 are important for every biological process that goes on inside you. Keep this in mind as you make decisions about water for you and your family. The decision you make can have a big impact on your health, the health of the planet and your pocketbook.

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