A few weeks ago, I realized that almost all shower filters articles on the internet are half wrong.
For instance, there are so many prominent blogs that promote KDF shower filters as ‘water softening showerheads. Anyone who knows how KDF works, knows that it cannot soften water.
So much mis-information. I can’t imagine how so many websites at once can be so misleading. All for selling a product? Seems quite unethical to me.
Which is why I created this article- the only article you’ll need to read before deciding which shower filter to buy. I’ve been using a shower filter for close to a year myself, so I know a few things about them, and I also spoke with representatives of 3 different shower filter companies.
There basically are three major shower filtration media in use today:
- Vitamin C
- Coconut Activated Carbon
Let’s get into these one by one.
KDF or Kinetic Degradation Fluxion shower filters are the most versatile, which is why they are also the most popular. More than half of the shower filters in the market today, use KDF filter cartridges. Even for the 8 shower filter brands surveyed for this article, 5 are KDF based.
Here’s a brief of what KDF filters can do:
- Remove free chlorine(90-95%)- certified by NSF/ANSI Standard 177
- Remove some amount of water soluble heavy metals- Not certified for this
- Control scale formation due to hard water
- Reduce bacteria
- Control algae growth
- Work in hot and cold water both(upto 115 degree Fahrenheit or 46 degrees Celsius)
What KDF filters can’t remove from water:
- TDS(Total dissolved salts)
- Chloramines- byproduct of chlorine and ammonia being used together for water purification in some places instead of just chlorine. Read more about chlorine/chloramines and how to remove them here
Also- unless you’re buying a premium brand- KDF shower filters are quite affordable(In the range of 10-30$ and about 10-15$ per replacement filter cartridge).
All in all, great value for money.
How do KDF filters work:
KDF shower filters are made using a patented blend of Copper and Zinc, which create a small electric charge as water flows through the filter cartridge. This tiny electric potential is enough to trigger a chemical process called oxidation-reduction(redox).
In a nutshell, redox means that two oppositely charged particles react, with one losing electrons and the other gaining. Say, free chlorine ions are present in the water, as they pass through the KDF media, they’ll lose electrons and get converted to a harmless, water soluble chloride, and will be passed along with the filtered water.
Other contaminants, such as heavy metals are plated out or retained on the surface of the filter- again, not completely, but to some extent.
KDF shower filtration efficiency depends on the flow rate of water, i.e: how long the water stays in contact with the filtration media. This is because the optimum flow rate for the redox reaction to occur successfully is about 2-2.5 GPM (7.6-9.5 LPM).
Unless you already have low water pressure at your home, you don’t need to worry about flow rate. You may want to or already have attached a water booster pump for your bathroom if you do have low water pressure.
Personally though, I’ve been using a KDF shower filter for close to 8 months and I’ve faced no problems with water pressure.
KDF shower filter maintenance:
KDF filters need to be replaced every 6 months or so(depending on how bad your water quality is). However, there is one thing you can do to extend the life of your KDF filter considerably- Backwashing
During normal usage of the shower filter, contaminants in water get trapped on the surface of the shower filter, which over time, may start restricting the flow of water. You may notice this happening by a drop in water pressure. Backwashing is done simply to remove these trapped contaminants and allow easy passage of water again.
Here’s how you do it:
- Simply take out the filter cartridge and put it back upside down in it’s housing, such that the input and output ends are now swapped.
- Now, run purified water through the shower filter for 2-3 mins. Doing this allows trapped contaminants to be released, as they flow out of the cartridge, through the ‘input’ end.
- After a couple of minutes, put the filter cartridge back in the original position and run water through the shower filter.Chances are, you’ll notice an improved flow rate and slightly better water quality.
- Repeat this process at least once every month(or more frequently if your water quality is bad)
Vitamin C Shower Filters:
Vitamin C shower filters aren’t for everyone because they solve a very specific problem. However, they solve it better than any filter out there.
What Vitamin C or ascorbic acid is great at, is removing chlorine and chloramines. So good, in fact, they can remove upto 99% chlorine and chloramines from water.
Technically speaking, Vitamin C doesn’t filter out chlorine and chloramines from water. Rather, it neutralizes the chlorine/ chloramines as the water flows through the filter cartridge. Which is why, over time, the Vitamin C serum gets depleted, and needs replacement.
Vitamin C shower filters are mostly priced around 60-90$ and last about 3 months– half the time a KDF filter will last.
Keep in mind though, that while most households around the world receive chlorinated water, chloramination is a relatively recent trend and isn’t practised as widely. Which is why, in my opinion, most households could do just as well getting a cheaper KDF filter that removes chlorine.
If you are unsure about your water containing chlorine, chloramines, or any other contaminants, just read up on your water suppliers annual Consumer Confidence Report(if you’re in the US) or get a simple home water testing kit, such as this one on Amazon.
Coconut Activated Carbon Filters(CAC):
The better, improved version of Granular Activated Carbon(GAC) filters. Coconut activated carbon(CAC) filters efficiently remove chemicals such as chlorine, chloramines and VOCs, along with improving odor and taste of water.
CAC filters are used more often because of a number of advantages over GAC, the most important of which is, that CAC filters work well in both, hot and cold water. In fact, I emailed Aquasana(which uses both KDF and CAC in it’s shower filter) to confirm this point and this is what they said:
A note: Some of you may have read about magnetic and electronic shower filters, and may be wondering why they aren’t included here. That’s because they are a hoax- simple as that. There is absolutely no science behind the claim that, in the case of magnetic shower filters- that electromagnetic waves soften water. Spare yourself disappointment and stay away from these.
Popular Brands and What Their Filters are Made of:
Sprite – Chlorgon:
Similar to KDF, Sprite has developed their own filter media that works on the redox process. Other than the fact that Chlorgon is made up of a blend of Copper, Zinc and Calcium Sulfite(KDF is made up of the first two only), there seem to be no differences performance wise. They both have the same NSF/ANSI certifications- Standard 177- which certifies them for removing free chlorine from water.
This product is a mix of proven science and unproven(rather disproved) science.
Rainshow’r shower filters use a combination of KDF(proven benefits) and Quartz crystals(unproven benefits)- which are quite popular in alternate therapy circles.
While they admit that they don’t have any scientific backing to their claims, Rainshow’r says on it’s website that they have observed Quartz crystals give water a lighter feel, probably because they create microclusters and impart negative ions to the water. They also make other claims such as reducing scale formation which they do not provide evidence for.
I’m not particularly opposed to Rainshow’r even, because unlike other companies selling such products, they don’t seek to hoodwink the consumer- in fact, they admit outright that they cannot verify their claims. However, they still believe in them.
Which is why, if you want to experiment with Quartz crystals and see for yourself- I will recommend you buy a Rainshow’r filter- because regardless of whether the crystals actually work- we know that KDF does work, and at least you’ll be showering safe.
Probably the best shower filter in the market today. The reason I say so is that they use a clever combination of KDF and coconut activated carbon shell. I say clever because both KDF and CAC have their limitations while used alone, but together, they’re capable of removing chlorine, chloramines, VOCs, THMs, as well as other organic chemicals from water.
The only drawback is that Aquasana’s filters are quite expensive, almost as much as Vitamin C filters- roughly around 60$. Their replacement cartridges too, cost about the same, so all in all, they can be quite costly.
Still, the best filter in the market has to come at a premium. You can check them out on Amazon.
Sonaki and UBS Vitafresh:
The reason these two brands are together is because they’re the only two brands that make Vitamin C shower filters. Comparatively speaking, Sonaki is the more popular brand and has better reviews, however, essentially, both products are the same.
Given how widely Vitamin C is used for neutralizing chlorine and chloramines, it is strange that these brands do not have an NSF/ANSI certification like all other KDF filters have.
Also, I came across a couple of customers online complaining of the short lifespan of Vitamin C filters. One user on Amazon said he needed to replace the filter cartridge within 4 weeks! The thing is, that the lifespan for any filter depends on how many contaminants are present in your water, so the filter life will vary from place to place
Still, there aren’t better products for removing chlorine and chloramines from your water than these two. Check them out on Amazon.
These shower filters use calcium sulfite filters, which they claim come with a whole host of advantages. However, nowhere on their website does their blog post on this topic ever explain how the technology actually works. Even an exhaustive research online showed up no legitimate source of information regarding calcium sulfite filters.
Add to this the fact that their filters aren’t NSF certified(at least yet):
For lack of knowledge on this one, I won’t recommend Aquabliss. In case you know about Calcium Sulfite water filtration, please do take the opportunity to comment below and educate me as well. I’ll include it in this post.
The Culligan brand is extremely popular online, and although theirs is a standard KDF shower filter, it still sells like hot cakes online- probably due to brand value. A great buy, check them out on Amazon.
I recommend you get the Aquasana shower filter. It gives you the best overall protection from maximum number of contaminants- more so than any standalone KDF or Vitamin C filter can possibly provide.
Here’s my rule when it comes to shower filters:
If you’re looking to remove just chlorine and chloramines from your water- get a Vitamin C filter. In other cases- get a KDF filter. As I said earlier, they filter out a wider range of contaminants and have more benefits for a general user than just a Vitamin C filter.
Hope you find this post helpful for buying your new shower filter! Don’t hesitate to jump into the comments section for any questions!