Whole House Water Filters

Whole house water filters are attached to the main water supply line to your house. All the water entering your home is treated. The faucets, toilets, shower, laundry room and all other water sources dispense filtered water. The goal of some filters is to produce better tasting water. Others aim to reduce contaminants and protect your health. If you are only concerned with taste perhaps an under sink filter is all you need.

If you want to safe guard the water that reaches your family, this is more important especially for pregnant, young, older or people with compromised immunity. Before deciding what whole house water filter is the right one for you, you will need to identify what contaminants are in your water.

The first source of information is the local water utility. You can request a copy of their annual water quality report. It is also recommended that you have your water tested for lead. The amount of lead will vary from house to house so this is one test you’ll need to get done on your home specifically.

Contaminants fall into three basic categories. They are sediments, chemicals and iron.


Sediment contaminants refer to actual particles in the water. This includes sand, dust, dirt and rust. Water that is heavily contaminated with sediment can be filtered through a succession of filters. Each one gets finer than the last. It is possible to reuse these filters.


Most chemical contaminants can be removed by activated charcoal. These types of filters are available in under-sink units, countertop and faucet filters. Even if you install a whole house filter you may still want to add an activated carbon filter for safe drinking water.

Activated carbon traps impurities with positively charged and absorbent carbon. These filters can remove most chemical contaminants from your drinking water supply. This includes chlorine, heavy metals, pesticides, VOCs and some parasites. This list is by no means conclusive. You will need to check the filter’s actual certification standard for its ability to remove chemicals.


There are two types of iron that can be found in house water. The first is called ferrous, dissolved or clear. The send is called ferric, which is rust or red colored iron. Ferric iron can be removed with a sediment filter. Ferrous iron must be removed through oxidation or ion exchange.

Other Considerations Before Purchase

These other factors should be taken into consideration when choosing the right model of water filter for your house. The flow rate is measured in gallons per minute (GPM). The flow rate determines the amount of water available for household use.

To figure out your required GPM refer to the demand ratings on each appliance. In order to provide an average sized house with uninterrupted water flow, a whole house filter needs to have a minimum flow rate of 10 GPM and preferably more.

The larger the size of the filter, the longer the duration between servicing and cleaning. Filter size also affects the amount of water flow and the amount of water pressure. Adequately sized whole house filters are 4.5” x 20”.

The length of the life of the filter is determined mostly by the amount of sediment that it will have to filter. Another factor here is the quality of the filter. The cost of replacing the filter is also determined by the quality. A more expensive but high-quality filter will usually save you money in the long run because of its durability. A good 4.5” x 20” filter will last 100,000-150,000 gallons.

The best port size for whole house filters is 1”. Anything smaller may not allow enough water flow to supply the house with continuous water with even pressure.

A good warranty is another thing to keep in mind. Delivery and installation costs, service and maintenance schedules are some other factors.

The final matter to consider would of course be how much you can afford to spend in the initial set up and resulting maintenance costs.