H20 101 - Water at Home

So you've vowed to switch to tap water. Smart choice! But sometimes our tap water isn't as crisp as the stuff that comes from the bottle. Que: the water purification system. But which method works best? Do water filtration pitchers really work as well as under-sink or whole-house models? How do you know what the system is filtering out ... and what exactly should you be filtering out, anyway?


Fear not! Our experts list this step-by-step guide to water purification in this month's Ask the Expert blog.

Step 1: Find out what's in your water. Before you choose a filtration system, you need to know common contaminants you want to remove. Using an at-home test kit or getting in touch with your water utility to find a local lab is the best way to check your water quality. Most municipalities release annual water reports, which are also useful sources of information.

Step 2: Figure out what type of filter you need. Activated carbon filters, the type found in many water pitcher filters and under-sink models, can remove heavy metals (like copper, mercury and lead), chlorine, pesticides, parasites (like giardia) and some VOCs. Other contaminants must be removed using a different type of purification system — perchlorates (the chemicals used in dry cleaning) can be removed only by reverse osmosis, and arsenic must be removed through distillation. 

Step 3: Decide the filter's location. You can choose either a whole-house (also called point-of-entry, or POE) filter, which filters the water before it enters your home or a point-of-use filter (POU), which filters the water just before you use it. Point-of-use filters include faucet and under-sink systems, pour-through water pitchers, and water bottles. Here are some points to remember when deciding what suits you and your home:

• Whole-house models are most often used to remove mineral deposits and unpleasant odors or tastes; you would still need to supplement a whole-house filter with another type to remove other contaminants. If excessive chlorine in your water bothers your skin, you may also want to consider a filter that attaches to your showerhead.

• Undersink or water pitcher: Which to choose? Undersink models tend to work more effectively than water pitchers and bottles, thanks to the added pressure forcing water through the filtration system — and you have the option of choosing a reverse-osmosis filter. Undersink models have the added benefit of filtering as you use, so there's no need to remember to refill the pitcher, but they are also more expensive to install. So what's the bottom line? If you are looking for a quick, inexpensive solution (or you are a renter) and a carbon filter is all you need, a water pitcher is the way to go. If you are looking for a more permanent solution or need more filtration than an activated carbon filter offers, get an under-sink model.

Step 4: Find a filtration system that is NSF certified. The single most important thing to look for when you are shopping for a water filtration system, whether it is for your whole house or it's a simple pitcher, is that it is certified by NSF International — when you see the NSF seal, that means the product or system has been tested to ensure it actually removes the contaminants it claims to remove. If you need help finding a water filtration system that is certified for the contaminants in your water, check out their website.

Step 5: Maintenance: Change those filters! Once you have installed a water filtration system or purchased a new water filter pitcher, you need to regularly change the filters and keep everything clean and running smoothly. If your system does not include an automatic timer or sensor to let you know when you are due for a new filter, make sure you note the date on your calendar. Changing water filters promptly according to the manufacturer's recommendation is the best way to ensure that your water is being thoroughly cleaned.