Shower filters are known to soften skin and hair and reduce ones exposure to chemicals commonly found in tap water. What is not as well known is the mechanism by which the shower filter media reduces these chemicals.
When possible, a high quality whole home water filter with carbon and KDF media is the ideal way to improve the quality of bath and shower water. By using this method all the taps in the house offer filtered water. The disadvantage to this approach is however that water that does not need to be filtered is filtered. For example, toilet flushing water, lawn irrigation, dishwashing water etc. Also, installation costs can be prohibitive where construction is necessary to make space for the equipment. In those situations where the costs of a whole home water filter system outweigh the benefits a high quality shower filter in the bathroom and a high quality point of use drinking water filter (countertop type or under sink type) can be an economic solution.
In the 1980's several companies introduced shower filtration devices that utilized KDF media. The KDF media uses the chemical processes of reduction and oxidation to clean the water. To have a comfortable shower, a flow rate of 2.5 gallons per minute is desirable. To get this kind of a flow rate with a carbon based filter would require a filter cartridge the size of a small microwave oven! The adsorption process, the process by which carbon reduces chemicals in water, requires adequate contact time with the carbon media. To make this contact time adequate you can either increase the amount of carbon media (thereby increasing the carbon surface area) or decrease the flow rate of the water – which is of course undesirable. The KDF media on the other hand requires very little contact time for the chemical processes of reduction and oxidation to take place. This makes KDF ideal for a shower situation and is the largest reason that all modern shower filters contain KDF. Shower filter manufacturers will often also include other ion exchange medias (often proprietary) or even some carbon.
Since KDF is found in almost all shower filters, the differences are found in the amount of KDF media, the style and shape of the filter housing and the type of shower head. Shower filters are available in a wide variety of styles and types.
Disposable – The entire housing is discarded at the end of the media's life span. These are available with and without a shower head.
Refillable – A replaceable cartridge allows the housing to be used again and again. These are available with and without a shower head.
Handheld – with a hose and removable wand.
Extension – with a shower head that can be articulated in any number of positions.
With so many options, it is easy to find a shower filter that fits your needs and preferences. We would recommend those with NSF certification so you can be assured that the filter is performing as advertised.