Why do you want to filter the water leaving your shower? You barely drink any of it so what’s the big deal?
Water utilities will use either chloramine or chlorine, but not both, to maintain a disinfectant residual in the potable water. Maintaining this residual is a regulatory requirement meant to make sure the water remains pathogen free after it leaves the treatment plant. Typically, large utilities will use chloramine because it does not dissipate as quickly and it will produce fewer disinfection by-products like THMs and chloroform. Maximum allowable levels of disinfection by-products are tightly controlled by the regulatory agencies. Suffice it to say the disinfection by-products issue is highly complex and heated. For more information on this topic, I recommend you start at EPA’s website dedicated to this issue.
I admit you’re much more likely to get hurt in the shower by slipping on that pesky bar of soap; however, there are certainly some nice advantages to filtering water in the shower. Following are a few reasons we use shower filters in our home.
- Skin is the human body’s largest organ and chlorine dries it out.
- Chlorine also robs hair of its moisture.
- Chlorine strips hair and skin of it’s naturally protective oils.
- Organic chemicals in the water can volatilize and be inhaled while showering. This is especially true of disinfection by-products like chloroforms and trihalomethanes. When inhaled, these chemicals can enter your system even faster than when ingested.
- Can reduce rotten egg smell in waters containing hydrogen sulfide.
- Chlorine can aggravate respiratory problems like asthma and allergies
Common Filter Medias for Shower Filters
KDF is highly effective at removing free chlorine, hydrogen sulfide and some metals. However, it does not work as well as carbon if your water utility uses chloramines to maintain a disinfection residual in the distribution system. Check the water quality report sent out by your local utility to find if they are using chlorine or chloramines. If it is chlorine, KDF alone may work fine. If they use chloramines, make sure the shower filter also includes carbon or GAC (Granular Activated Carbon).
Even if your water utility uses only chlorine, we still recommend using a KDF and carbon filter media if your water supply is from a lake or stream. This is because chlorine reacts with the organics in the water to form disinfection by-products. KDF does little to reduce these by-products, but carbon is highly efficient in adsorbing them. The carbon media also effectively removes other trace organic chemicals and pharmaceuticals that are commonly found in surface waters.
KDF only shower filters are fine if chlorine is the disinfectant and the source water is from wells. Few organics exist in groundwaters; therefore, few disinfection by-products are formed.
Unless you have a good understanding of the disinfectants used by the utility and where the water originates, we generally recommend getting a shower filter that has both KDF and carbon. This provides the widest range of treatment and the KDF helps extend the useful life of the carbon media.
For more detailed information on KDF and carbon filter medias, you can check our article KDF vs Carbon — Which is better for my home filter?.