The Best Shower Filters

The Best Shower Filters

I just replaced my shower filters, so I thought I’d update my best shower filter review from earlier this year. Each update to the review generates a lot of useful comments. So I’m incorporating what I’ve learned from those comments into this latest review.

Why filter your shower? Well, because your skin is really good at absorbing things. For example, about 60% of the chlorine that is absorbed daily comes from showering in chlorinating water. Because most of us shower under tap water, we absorb things like chlorine, chloramines, heavy metals and VOCs through our skin on a daily basis. Ideally, we’d like to get rid of all of those contaminants. But that’s really only possible if you filter the water as it enters your house using a whole house filter. So most of us are stuck with filtering water at the showerhead, and that’s not optimal. In a shower, the water moves fast and it’s under high pressure. This makes filtration difficult. Also, the water is typically hot, which makes filtration difficult too.


Let’s now look at the three main types of shower filters: KDF (Kinetic Degradation Fluxion) Filters, Carbon Filters and Vitamin C filters.

KDF Filters are by far the most popular shower filters in the U.S. KDF filters remove free chlorine by reversing the electrochemical process that originally separated the chlorine from sodium in a brine solution. However, KDF filters suffer from two major limitations: they don’t perform well in hot water, and they don’t remove chloramines. Chloramine or NH2Cl (a combination of chlorine and ammonia) now commonly being used in place of chlorine for disinfection. This is because chloramine does not dissipate as easily as chlorine. But this also means it is harder to remove from water. Even the best KDF filters can’t remove chloramine, but they are reasonably effective at removing chlorine. KDF filters last about 6 months. The best rated KDF filters are made by Aquasauna and Sprite.

Carbon Filters are useful for removing certain organic chemicals and chlorine in cold water. Chlorine is attracted to and held (absorbed) into the surface of the carbon particles. However, the efficiency of absorption is basically nullified when the water becomes warm. When used in a showerhead, activated carbon is only effective for a short time — the filter gets clogged quickly by sediment in the water.

Vitamin C Filters are commonly sold in Asia, but they are difficult to find in the U.S. Vitamin C filters are simple — they contain a large block of Vitamin C (ascorbic acid), and water runs through the filter and comes into contact with the Vitamin C. The Vitamin C neutralizes about 99% of the chlorine and chloramines in the water. Vitamin C filters last about 6-12 months, and their effectiveness does not diminish until the Vitamin C is used up.

Here are the chemical equations:

When Vitamin C reacts with chloramine, the byproducts are dehydroascorbic acid, ammonia, and chloride (beneficial to the body).

When Vitamin C reacts with chlorine dissolved in water, the byproducts are dehydroascorbic acid (another form of vitamin c) and hydrochloric acid (in minute quantities).


A fellow who goes by the alias ReviewGuy did an independent test of the different shower filters, you can read about his results here.

Vitamin C filters are really the only type of shower filter than works consistently, especially if your water contains chloramines. Unfortunately, many Vitamin C filters are cheaply made. Here’s my review of the different products available:

Sonaki Vitamin C Handheld Showerhead Chlorine Filter

Sonaki Vitamin C Showerhead Filter
Sonaki Vitamin C Showerhead Filter

The Sonaki Vitamin C Handheld Showerhead Chlorine Filter has the best build quality I’ve found. It costs about $90, and it comes with a low-flow showerhead. The showerhead has two spray patterns and an off  switch. I like the feel of this showerhead, and the fact that the filter is transparent, so you can see when the Vitamin C has run out. It also comes with two replacement Vitamin C cartridges. It’s available from Amazon for $90.

Sonaki VitaMax Vitamin C Inline Filter

Vitamax Inline Vitamin C Shower Filter
Vitamax Inline Vitamin C Shower Filter

The Sonaki VitaMax Vitamin C Inline Filter is a good choice if you already have a showerhead you like. This filter fits in-line and works with your existing showerhead. It costs about $50, and it’s available from Amazon.

In my home I currently use a Sonaki inline filter attached to a Culligan shower filter (this is an expensive charcoal shower filter). This combination looks makeshift but it works quite well once installed. The Sonaki filter is for chlorine and chloramine removal, and the Culligan filter is to remove scale, rust and other contaminates.

Update: Here’s a study on ascorbic acid and chloramines.

Thanks to Darren and SteveG for their research.

42 thoughts on “The Best Shower Filters”

  1. Carol,

    The San Francisco Public Utilities Commission states that Vitamin C can be used to remove chlormaines from tap water. Here is the quote from the Commission:

    “Vitamin C (ascorbic acid) has recently been included in AWWA Standard (AWWA, 2005b) as one of the methods for dechlorination of disinfected water mains. SFPUC and other utilities have used Vitamin C for dechlorination prior to environmental discharges of chlorinated and chloraminated water. Since ascorbic acid is weakly acidic, the pH of water may decrease slightly (Tikkanen et al., 2001). Ascorbic acid has been used for a long time as one of the dechlorinating agents for preservation of chlorinated or chloraminated water samples for laboratory analysis.”

    The full document can be found here:

    I’ve also been planning on doing my own tests of the shower filters.


  2. Hi.
    This is all great, and I’ve read every word of your piece, Justin, and also ReviewGuy’s. I’m still confused about chloramine, because I’ve read elsewhere that vitamin c doesn’t remove it after all ???? This website – – from a group in the San Francisco area concerned about chloramine, insists it doesn’t. They sound like they’ve really looked at it, but so have you. How do I reconcile? I’d really like cleaner shower water.
    Thanks very much,

  3. So glad I read this, so I didn’t make the mistake of getting a KDF filter I looked it up and my city does use chloramine. So that would have been bad. Thanks for saving me from that!

  4. Great article, and THANK YOU.

    QUESTION: I am looking at two options – can you please tell me which you’d suggest?

    Vitamin C based: Sonaki option you mention, OR

    Recommended by as top choice:
    (comparison chart:

    Any suggestions? Want to purchase soon. Thank you SO much.

  5. Is there a shower filter that takes out the chlorine, chloramines, AND metals and chemicals? The vitamin C shower filters seem good for chlorine & chloramines, but not for metals and chemicals.

  6. With research done into shower head filters, this one has come up tops. Experientially it has also been proven to be satisfactory in terms of the ‘after effects’ versus regular shower head filters.

  7. i thought after researching that the sonaki shower filter would be the best but ‘after’ i just ordered it, i saw reviews that said it takes your water pressure and that the replacement filters are lousy. i need a filter i can use with my shower head that won’t take all the pressure, any suggestions? thanks.

  8. Wow! Thanks for all the info! That explains why everyone’s hair in our home is frizzed out and why our skin is so dry. Also… It could be why the females in our home get yeast infections! Thanks so much 🙂

  9. I use Aquaspace SF-350 (special aquaspace carbon and KDF), but they have a larger unit also. It lasts me at least 1 year (10,000 gallons I think). I still try to avoid the shower because my skin is so sensitive to the few chemicals that do make it through and even to natural soap. I use a space heater in the bathroom, since it helps me keep the shower temperature down as low as possible.

  10. I allergic to Sufides, chlorine! I tried all the shower filters and they dont seem to work! This Vtia shower worries me! When Asorbic acid(vitamin C) and Chlorimines make contact is creates Hydrochloric Acid. Is it not dangerous to breath in that gas too? Plus Vitamin C shower filters only neutralize chlorine and chlorimines not any other harmful metals and chemicals! Which is the best for me?

      1. Great article Justin. Thank you for sharing. I have the same concern as Ingrid and Troy:

        Effect of Hydrochloric acid (minute quantity) on human skin and when inhaled? Would really appreciate your take on it. Thanks.

        1. Marshal,

          I haven’t found an authoritative answer to that question. But I’ve heard that the acid is so weak and diluted that the effects are negligible.


          1. Thanks Justin.

            I am just afraid that we are replacing one harmful substance with another. Both HCL acid and Chlorine are dangerous to human health. I don’t know at what low concentrations they cease to be dangerous and which one is comparatively safer in minute quantities.

            I will keep looking for more information on this and post it here if I come across something. Please do the same. Thank you again for your prompt response.

  11. Very Nice breakdown on the top shower filters. I like how you talk about each kind of filtration system available and I’ve never seen the vitamin c filtration set up.

    Great idea for a post and very well done!


  12. Great article – I had no idea you reviewed our products, but I am very glad you did. Just in case your readers are interested, we sell Sonaki vitamin c shower head filters for cheaper than what is available amazon, we have a great deal handheld shower head filter models to offer, and we have a 60 day money back guarantee.
    moby – no, your filter is not defective, the water is infused with the vitamin c at the top of the shower filter cartridge.
    efficiencyseeker – yes you can, and of course Sonaki vitamin c shower filters are the best…but I may be biased.

    Great read!

    1. i have read bad reviews that the sonaki shower filter takes your water pressure and that the replacement filters are no good. i was very excited to have ordered one but after reading those reviews i cancelled. i need a filter to use with existing shower head that does not take all the pressure. any suggestions?

  13. Can you recommend a shower filer that i can use with ANY showerheads? I want to use a handheld but handhelds don’t have a good filter which lasts atleast 6 months. So I thought I can find a good filter that blocks out as much as it can (chlorine, metals, rusts.. ect…) that is universal with other showerheads? Can you recommend please?

    The Sonaki looks great but ONLY has vitamin C right so it doesn’t block out the metals and more. So do you know I can get the Vit. C inline filter than get a April shower oxygenics filtered showerhead? But this vit. C inline has to be changed every 3 months? What do you think? Oxygenics seems great cause it saves the water but oxygen pressure which is good for the pores. then I’m thinking about getting the baby handheld showerhead. Would love to get your opinions.

  14. I got the Culligan MHD I believe its called the other week and have noticed a huge difference in how I feel after I take a shower. I used to feel very fatigued and dehydrated but the filter immediately made a difference. My breathing is also improved as well!

  15. EfficiencySeeker

    I have two questions. 1. Can I attach my handheld shower head to the Sonaki VitaMax Vitamin C Inline Filter?
    2. How does the Sonaki VitaMax Vitamin C Inline Filter compare to the chlorine filter VshowerUSA or the VitaShower SF1?

  16. EfficiencySeeker

    I love these MetaEfficient articles. There aren’t too many other websites on the net that review these kind of items. Usually they are just stores trying to pass off their sales pitch as articles.
    Keep up the good work, Justin!

    1. Makir, this is from Wikipedia (not necessarily the best source, but is sometimes a good start):

      “Toxicity and storage information”

      “The toxicity of ammonia solutions does not usually cause problems for humans and other mammals, as a specific mechanism exists to prevent its build-up in the bloodstream. Ammonia is converted to carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase, and then enters the urea cycle to be either incorporated into amino acids or excreted in the urine.”

      Compare what I’ve quoted here to the well-known toxicity of chlorine.

  17. As a builder, I really appreciate this information and your site in general. People often fail to remember that all the little things add up, and that they play a crucial role in making their home green. Good information! Thanks

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