Home Drinking Water Filters & Purifiers
Technically, everyone's drinking water at home does not need treatment. If you live in the United States or another country where city water suppliers have strict rules about the quality of the water they produce, then tap water will already meet high drinking standards.
Testing Water Quality
Water utilities in such locations are required by law to test the drinking water several times per day to make sure it's healthy. They are very aware that anything off could affect hundreds or thousands of their customers. In fact, to make doubly, absolutely sure they add chlorine or another similar disinfectant, after they've treated, to keep the water microbe-free until it gets to your tap.
Unfortunately, chlorine, in large or small steady doses, is harmful to the human body. Just as it kills microbes in the water supply, so it kills microbes in your own body, including the good ones. This is why most city people choose to set up a drinking water filter - to take out the chlorine, and improve the taste and odor. For that you really only need a simple carbon filter.
On the other hand, people who use well water or rainwater, rather than city water, or who live in countries where standards are not so strict, or who have serious health problems, all would be helped by using one or another of the following water treatment methods.
Filtration is the process of passing unclean water through a block of porous material that prevents particulates from following. The water emerging from the other side is cleansed of any material bigger than the hole size it had to pass through. The ideal size hole for a high quality filter is 0.1 microns, which takes out floating debris, as well as any microbes bigger than that, like giardia and cryptosporidium, which cause diarrhea.
Carbon Filter - This type of filter pushes water through a series of layers of granulated material, as least one of which is activated carbon (same as the activated charcoal you ingest in pills to reduce gas). The other layers remove most impurities and nonorganic materials (like metals), while the carbon layer catches organics and removes chlorine and any gases. Sometimes silver is added to this layer to prevent entrapped microbes from colonizing there.
If you live in an area where tap water is fairly clean and is treated to kill microbes, this is all you will need to keep your drinking water healthy. I've had a Multi-Pure carbon filter for about 10 years and have been fully satisfied with it.
Reverse Osmosis - This is the system most commonly employed by the military. It entails running water through several membranes, or filters, each doing a different job. The sediment filter traps particles, the activated carbon filter traps organic chemicals and chlorine, and the RO filter captures the rest. There is some worry that it takes out trace minerals and metals that are actually healthy for our bodies.
This system is called "reverse osmosis" because water's normal movement is to flow from a pure, light state toward a more condensed state (osmosis), whereas the RO system forces water to move through filters from a more congested state to become more pure - the reverse of what it normally does. This is the system also primarily used to convert seawater to drinking water. It's a good, safe, thorough water filtering system.
Note: Both of these systems have filters that need to be periodically cleaned and replaced, which should be taken into account when estimating cost.
Purification is a process that creates chemical changes or is a chemical addition to the water that kills microbes. It's purpose is to decontaminate the water. This can include removing bad color, odor, or chemical additives like chlorine, but mostly is focused on getting rid of bacteria and viruses. It is often combined with a filtration process to remove the dead bodies of microbes killed by purification.
Tablets - Iodine tablets are the quickest and least efficient way to decontaminate water. These are generally used out in the field, where there is no access to electricity. The tablets do kill giardia and cryptosporidium, but they don't take out chemicals or other impurities.
If you need to use this method in an emergency, wait 1/2 hour after dropping the tablet into the water, then add some vitamin C to improve the taste before drinking.
- Boiling - "Make sure you boil your water before drinking" is one of the first pieces of advice a Peace Corps volunteer is given when they arrive in their host country. Boiling effectively kills most microbes and is a good prevention for waterborne diseases. People who are generally healthy and who eat well should be ok with this simple method of purification.
If your primary source of water at home is well water, this is a viable cleansing method for small amounts, especially if you combine it with a coffee filter to take out particles, while adding beans for flavor. If you live in a city where tap water is treated, the primary benefits of boiling are that it removes chlorine and is good for making tea.
Distillation - Distillation is a process where water is boiled and the water vapor is transported to a cooler, which cools it down into its normal water form, leaving impurities and chemicals behind, and killing all microbes. It has no taste, because there's nothing in it to give it taste. This process simulates the creation of rainwater. It uses a lot of energy - both for boiling and cooling the water.
In an area where rain water is used or tap water is suspect, but there is plenty of electricity, this is an excellent option. Here is a link to a home distillation system made in Sweden: [link - http://home-water-distiller.com/ ]
- Ultraviolet - This system was developed for use in hospitals. It combines a carbon filter with a separate chamber containing a short-wave ultraviolet light. The UV light is highly effective at disabling microbes, preventing them from reproducing and causing disease. The carbon filter generally requires replacement every six months, while the UV bulb will need to be replaced once a year. The bulb stays on all the time, so check to see how much electricity your chosen model will use.
This system is best used in an area where tap water is often unhealthy, seldom treated, and is easy to get sick from. If you have serious allergies that are aggravated by tap water, this would be a good system to use even where tap water is good.
Undercounter UV Water Purifier
Water Treatment Products
Water treatment systems take many forms these days. In addition to all those below, there are also smaller portable filters for travelers and larger whole house systems that clean your entire water supply. Here are a couple of the types you can purchase in the United States for kitchen use. They are the brands rating most highly for each type on Amazon.com. Feel free to explore Amazon for other types and their ratings as well.
Note: I am focusing on filter types here, not advocating the brand that shows. The two descriptions below are customized to inform you about the type of filter and how it works. The prices showing up give you an overall idea of how much each type costs, and their photos show you the difference in types better than I can describe. Always include cost of replacement filters in your calculations.
You will have noticed that the types shown above are water filters, not purifiers. Unfortunately, that appears to be what Amazon sells. If you enter "water purifier" in the Amazon search box, the results still show filters, so if you are interested in UV or distillation purifiers, you will have to do a Google search.
Buying a Water Filter or Purifier
All benefits of these different types of filters and/or purifiers will not apply to each person. Therefore, it's important to look at your own situation carefully.
- What is contained in your tap water that needs taking out? Look on your water bill for your utility's website. Go online to see what their water consists of and what the pH level is. If you don't find anything, purchase a water testing kit and measure it yourself.
- How many people are in your family? A larger family will want to use a system with a larger capacity. If you are anxious about chlorine absorption through the skin or lungs of your family while showering, a whole house system would give you clean water throughout.
- How much room do you have on your counter? A smaller place may not have room for a countertop system, but may have lots of room in the refrigerator or under the sink.
- How much do replacement filters cost? It may be that a countertop will be cheaper than a pitcher type over time. Pick a time period - say three years. Figure out how many you'll need to purchase during that time (according to manufacturer's recommendations) and how much the total cost will be. Add that total to the cost of the system you are considering, then compare costs between systems.
Product Reviews - What Do Buyers Care About?
Once you have chosen what kind of system would work best for you, you will want to choose a good brand. For this, it's important to see how buyers experienced the brands you are considering. Always look at customer reviews. Even if you intend to buy in a local store, go online to find reviews first.
According to reviewers on Amazon.com, these are the things they looked for when determining whether or not a particular brand of filtration or purification system worked for them.
- What is treated - What is the product set up to do? Clean particulates? Kill microbes? Eliminate odors? Get rid of chlorine?
- Efficiency - How much water will it clean at a time? How long does it take? How well does it do what it says it will do? How easy is it to use?
- Quality - How well is it built and how long do its parts last?
- Design - How pleasing is the design to the eye? How much space does it take? Does it add to the kitchen or does it just look like clutter?
- Maintenance - Does it have an indicator to show when the filter needs changing? (One person living alone will change less often than a family of five.) How much do new filters cost? Can you buy adapters or valves if they need replacement? Does it have a well-written manual that shows how to maintain it?
Company service - How does the company react when you call with questions or problems? How long does it take for a knowledgeable company representative to answer the phone? How long does the warranty last and do they honor it?
When to Replace the Filter
Choosing your product carefully can net you many years of healthy and good-tasting drinking water. If you haven't thought about it before, take the time to analyze your needs carefully. If you have been thinking about it, maybe this article is the final thing you need to prompt you to make that purchase. Enjoy!