Read on to find out which water filtration system is best for your home.
Faucet-mounted filters
If you're looking for easy installation, these are a good choice for filtering drinking and cooking water. You simply unscrew the aerator from the threaded tip of the faucet and screw on the filter. Faucet-mounted filters let you switch between filtered and unfiltered water. On the downside, they slow water flow, and they don't fit on all faucets.
Countertop filters
These filters screw onto the faucet after you remove the aerator. They let you filter large quantities of water without modifying the plumbing, and they're less likely to clog than carafe or faucet-mount filters. But they can clutter a countertop, and they don't fit all faucets.
Under-sink filters
Like countertop filters, these can filter lots of water. But instead of cluttering the counter, they rob space from the cabinet beneath the sink. They also require professional plumbing modifications, and drilling a hole for the dispenser through the sink or countertop.
Reverse-osmosis filters
These use household pressure to pass water through a semi-permeable membrane. They can remove a wide range of contaminants, including dissolved solids, and they are the only type certified to remove arsenic. But you must sanitize them with bleach periodically. Eventually the membrane must be replaced. They can also be extremely slow, rob cabinet space, and create 3 to 5 gallons of waste water for every gallon filtered.
Whole-house filters
These are an inexpensive way to remove sediment and rust, and with some models, chlorine. Long cartridge life is another plus. But most whole-house filters aren't designed to remove many other contaminants, including cysts, metals, and volatile organic compounds. They require plumbing changes, but not at the sink or faucet.
For more information about drinking water, how to read your Consumer Confidence Reports, and why filtered tap water is often safer than bottled, visit the Consumer Reports' water filters guide at Greenerchoices.org.