Very few areas of the country have a pristine water supply. Even though tap water is treated before it gets to your faucet, it can still contain contaminants such as chemicals and heavy metals. In addition, virtually all municipalities chlorinate their water. Not only is chlorine a possible carcinogen, but it gives the water a very unpleasant taste. The vast majority of cities and towns also fluoridate the water supply; the dangers of fluoride have been well documented and many people want to remove it from their drinking water.
Buying a water filter is much cheaper in the long run than buying bottled water. But deciding what type of filter to buy can be confusing. Here we’ll review the different types of filters, along with their benefits and drawbacks.
Carbon-Block Filters
This is the most common and most popular type of water filter. It typically consists of granular activated carbon compressed into a block and encased in a cylinder-shaped piece of ceramic, which in turn is encased in a hard plastic housing. Carbon substantially reduces chlorine, chemicals, dirt, sediment and lead. The ceramic acts as a barrier, stopping parasites and most bacteria.
Carbon filters are economically priced and are available in countertop and under-sink models. Countertop models attach to the faucet, but the filtered water comes out of a separate spout attached to the unit. When you want non-filtered water, such as for washing dishes, a diverter switch or button sends the water through the faucet. Under-counter models require a hole to be drilled in the countertop to accommodate the filter spout. If you are handy, you can install it yourself; otherwise you’ll need a plumber.
Filters in carbon units need to be changed at least once a year, depending on the water quality.
Reverse Osmosis Filters
Most reverse osmosis (also called RO) systems contain two or three filters (depending on the model) plus a special membrane called TFC (thin film composite) that uses high pressure to separate contaminants from the water. The filters contain carbons, and some units also have a prefilter for sediment.
Because the water filters through several layers, these units take out more contaminants than carbon-only filters. In addition to the pollutants that carbon removes, RO works on heavy metals and fluoride. However, the extra filtration layers also mean that RO systems are slow—it takes three to four hours to make enough water to fill a typical holding tank. This becomes an issue with countertop units, which dispense water directly from the machine. If the tank is empty and you turn on the faucet, you won’t have any filtered water until it makes its way through the unit. Under-counter RO systems are more practical; most of them automatically start refilling the tank after you use water, although it still takes a few hours to fill completely. Under-counter models require a hole to be drilled in the countertop to accommodate the filter spout, as well as a plumber to install the unit (unless you’re handy with plumbing).
Another drawback of RO systems is that they remove the good along with the bad, stripping all of the beneficial minerals from the water. However, the water can be revitalized by adding trace mineral drops or by using an enhancement device. This is important not only for nutrition, but because mineral-free water becomes “aggressive,” which means it leaches from certain substances such as plastic. Therefore, it’s not a good idea to put RO water in plastic bottles. Use glass, or, for portability, lightweight stainless-steel bottles.
Generally, filters in an RO unit need to be changed yearly, and the TFC membrane should last 3 to 5 years.
Distillers
Distillers work by heating water to the boiling point (212 degrees), creating steam which cools and then condenses back into water. Impurities are left behind in the boiling tank. This method removes a very high percentage of most contaminants, including fluoride. It is also one of the few methods that definitively removes viruses from the water. (The other is ultraviolet light.) However, distillation alone does not remove all of the volatile organic chemicals (VOCs), so a good distiller will have a carbon filter for this purpose.
Distillers are available in countertop models and larger systems that can be connected to the drinking water supply. Countertop models are slow, taking several hours to make a gallon of purified water. Large units can be placed elsewhere in the home (basement, utility room), with the water pumped immediately to the sink using a separate spout (a hole needs to be drilled in the countertop to accommodate the spout).
Distillers, like RO systems, remove minerals from the water along with contaminants. However, the water can be revitalized by adding trace mineral drops or by using an enhancement device.
Other Methods of Removing Fluoride
If you want to remove fluoride but don’t want an RO system or a distiller, some manufacturers of carbon-block filters also have fluoride-removing units that use activated alumina. These filters are separate cartridges that need to be connected to the main carbon unit. Fluoride cartridges usually need to be replaced every six months. They do not remove as much fluoride as an RO or distiller.
Ultraviolet Light
Some vendors of carbon-block filters offer an ultraviolet (UV) light option for killing viruses and bacteria. UV bulbs need to be changed periodically.
Energizing Filters
Several companies offer systems that revitalize as well as filter the water. The water is often microclustered—broken down into smaller molecules, increasing its absorption into your body and hydrating you more quickly. Some systems use magnets to do this; other use a combination of special ceramics and stones that have energizing properties. In some units, the energizing media are permanent and do not need to be replaced. Others use replaceable magnetic disks.
Whole-House Filtration
If you want all the water in your home (all faucets, shower, laundry, etc.) to be filtered, there are many options for whole-house systems. Most systems use some combination of carbons to remove common contaminants like chlorine and chemicals; some add fluoride-removing media and some have prefilters for sediment removal. These filters are installed where the main water line enters the house. Systems start at under $1,000 and can run into the thousands depending on the features you want. Refills are costly because of the unit’s size.
Carafe Filters
If your budget doesn’t allow for a sink filter or if you want a filter for office or travel, then a carafe (pitcher) filter fits the bill. These units use a small carbon-based filter; water is poured in and drips through the filter until the pitcher is full. Because of the filter’s small size, it can take a while for the pitcher to fill up. Some carafe filters also have a fluoride-removing option.
It helps to know what’s in your water before you shop for a filter. Municipalities can provide you with a free copy of your local water report. If your water comes from a well, you can have it tested by a professional or you can buy a water testing kit. These kits provide you with containers; you take samples of your water and send it in to a lab, which sends you a detailed report. Lab fees are included in the cost of these kits, although shipping is generally not included. Also on the market are do-it-yourself kits; these are less expensive but don’t test for as many contaminants as the lab kits.
Article by Cutting Edge
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Worth the price on those kits if its going to keep things safe IMO.