Basically, there are two types of shower filters, namely the inbuilt and inline models. An inbuilt shower filter sits within the existing head. An inline filter gets connected to the pipe directly. Then you have to attach the showerhead to the filter at the bottom. Showerhead filters may be attached to the ceiling, wall, and hand-held models of showerheads.
The inline filter is stated to be better due to its variable size and number of media layers. Most of the modern filters use KDF in combination with the activated carbon. The number of media layers varies from 30 to 15, depending on the stages of operations. They include softening, cleaning, purification, disinfection, and energizing the water.
KDF filters are the standard models which use a combination of copper and zinc alloy for softening and cleaning. It is supposed to remove all the traces of chlorine, dissolved metals, algae, and microbes. The KDF filters use two types of media namely the KDF-55 and KDF-85.
The first type of KDF-55 can remove chlorine, hydrogen compounds and algae along with biochemicals. KDF-85 is an improved version which can remove highly dissolved volatile organic compounds, pesticides, and other forms of inorganic compounds from water. It can also remove the odor of infectious elements.
Activated Carbon-Medium: The activated carbon medium is mostly used in combination with the KDF or calcium sulfite medium. It can remove all types of microbes which are untreated by KDF. It can also improve the softness and taste of water molecules by adding the charged ions.
The other benefit of activated carbon is the release of thermal energy in the form of potential energy. You can experience the rejuvenation effects after you take a 15-20 minutes shower under the filter fitted with activated carbon.
Calcium sulfite filter is stated to be an improved version over the KDF filters. The manufacturers claim that it can remove microbes of size less than 01 Microns. They also state the filter can eliminate volatile organic compounds, and fluoride to a considerable extent.
TFC membrane filter is known to be a sure cure for fluoride problem. It is stated to be effective due to the reverse osmosis process or ion exchange process which can remove the highly dissolved fluoride completely. However, there seems to be a catch with such filters. They can also remove many of the useful and healthy minerals like phosphorous, copper, zinc, etc. Hence, it may be combined with KDF, active carbon, and germanium media to restore the lost minerals.
Multi-stage filters may use a combination of KDF, calcium sulfite, activated carbon, germanium, ceramic balls, TFC, PP-cotton, and radium irradiated medium. This filter can eliminate the germs and pathogens completely from the water. In fact, it can transform the hardest water from municipal and well sources.
You may choose any type and model of shower head water filter, depending on your need. It should be able to function with the same level of efficiency for hot and cold water.