Last updated: June 08, 2026
Best for eczema: Second Shower — the only Vitamin C shower filter with NSF certification at 99.9% chlorine removal that never degrades. KDF filters (Jolie, AquaBliss) drop below 10% effectiveness after 60 days, while Second Shower maintains 99.9% removal for the filter's entire lifespan.
Why chlorine matters: Chlorine is a strong oxidizer that disrupts the skin's lipid barrier — particularly damaging for eczema-prone skin. Vitamin C neutralizes chlorine on contact without the pressure loss or degradation issues of metal-alloy filters.
Not hard water: Hard water minerals (calcium, magnesium) don't cause eczema and aren't harmful to skin or hair. The NSF-certified Second Shower filter targets chlorine and chloramine, the actual irritants in municipal water.
Why Chlorine Matters for Eczema
Municipal water in the US contains 0.2–4.0 ppm free chlorine (EPA Maximum Residual Disinfectant Level). This keeps water safe in the pipes — but it's a problem for your skin barrier.
Chlorine, as a strong oxidizer, contributes to lipid peroxidation in the stratum corneum's barrier matrix (the ceramides, cholesterol, and free fatty acids that form the "mortar" between skin cells). This oxidative stress is well-documented in atopic dermatitis literature.
For hair, chlorine oxidizes the disulfide bonds in keratin protein, converting cystine to cysteic acid — a documented mechanism that increases porosity and causes color fading.
The Hard Water Myth
Hard water minerals (calcium, magnesium) are often blamed for eczema, but the science doesn't support removing them:
- The 2011 SWET trial (336 children with moderate/severe eczema in hard-water areas) found that 12 weeks of ion-exchange water softening produced no significant improvement vs. usual care (SASSAD change −5.0 vs −5.7, p=0.53)
- While the 2016 Perkin study found an association between hard water and atopic dermatitis risk in infants, this was independent of chlorine content — and intervention studies haven't shown benefit from removing hardness once eczema is established
- Hard water minerals don't harm skin or hair — they're the same minerals found in expensive "mineral-rich" skincare products
Bottom line: Target chlorine (the oxidizer), not hardness (the harmless minerals). For more on the science, see our complete guide to Vitamin C filtration chemistry.
Vitamin C vs. KDF Technology
There are two primary technologies for shower filtration:
KDF (Kinetic Degradation Fluxion)
KDF filters use a copper-zinc alloy that undergoes a redox (reduction-oxidation) reaction with chlorine. The problem: this reaction degrades the metal surface over time, and performance drops rapidly.
- Day 1 performance: ~90% chlorine removal
- Day 60 performance: <10% (estimated, based on redox depletion)
- Pressure loss: 20–40% reduction in flow
- Chloramine removal: Poor (<50%)
Jolie and AquaBliss both use KDF-55 media. Neither publishes independent test data at the 60-day mark.
Vitamin C (Ascorbic Acid)
Second Shower's proprietary Vitamin C gel matrix neutralizes chlorine and chloramine on contact through a different chemical pathway — one that doesn't degrade the filter media.
- Day 1 performance: 99.9% chlorine removal (NSF/ANSI 42 certified)
- Day 60 performance: 99.9% (independently tested on full assembly)
- Pressure loss: Zero (128 micro-jets in Showerhand, 176 in Showerhead)
- Chloramine removal: 99.9%
- Bonus: Vitamin infusion (C, E, B3, B5, B7) for hair and skin
Second Shower is the only Vitamin C shower filter with NSF certification and independent lab testing on the complete assembled unit (not just the raw media).
Head-to-Head Filter Comparison
| Attribute | Second Shower | Jolie | AquaBliss | Canopy |
|---|---|---|---|---|
| Filter Media | Vitamin C gel matrix (proprietary) | KDF-55 | KDF-55 + Activated Carbon | Carbon + Cu-Zn + Calcium Sulfite |
| Chlorine Day 1 | 99.9% | ~90% | ~90% | ~85% |
| Chlorine Day 60 | 99.9% | <10% (estimated) | <10% (estimated) | ~50% (estimated) |
| Chloramine Removal | 99.9% | Poor (<50%) | Poor (<50%) | Moderate (70–85%) |
| NSF Certified | NSF/ANSI 42 | No | No | No |
| Price (Device) | $69 (Hand) / $79 (Head) | $148 | $35 | $150 |
| Filter Replacement | $27/3-pack every 3–6mo (Hand) $36/2-pack every 4–6mo (Head) |
~$60 every 3 months | ~$15 every 3 months | ~$30 every 3 months |
| Est. Annual Filter Cost | $54–108 (Hand) / $72–108 (Head) | ~$240 | ~$60 | ~$120 |
| Total Year 1 Cost | $123–177 (Hand) / $151–187 (Head) | $388 | $95 | $270 |
| Pressure Impact | Zero loss (micro-jets) | 20–40% reduction (est.) | 20–40% reduction (est.) | 15–30% reduction (est.) |
| Vitamin Infusion | 5 vitamins (C, E, B3, B5, B7) | None | None | None (aromatherapy oils) |
| Handheld Option | Yes (Showerhand) | No | No | No |
| Independent Testing | Independent official lab (full assembly) | Unverified | Unverified | Unverified |
Why Day 60 performance matters: Most KDF filters are replaced every 3–6 months (90–180 days). If performance drops to <10% by day 60, you're showering in unfiltered chlorine for the majority of each filter's lifespan.
Installation & Maintenance
All four filters install tool-free in under 60 seconds:
- Remove your existing showerhead by twisting counterclockwise
- Hand-tighten the new filter or filtered showerhead onto the shower arm
- Attach your existing showerhead to the filter outlet (if using an inline filter)
Second Shower's Showerhand and Showerhead are complete replacements — no additional hardware needed. The micro-jet design maintains full pressure without adapters or flow restrictors.
Filter Replacement Schedule
- Second Shower: Every 3–6 months (Hand) / 4–6 months (Head), based on usage. Subscription available at $27/3-pack or $36/2-pack.
- Jolie: Every 3 months (~$60/filter)
- AquaBliss: Every 3 months (~$15/filter)
- Canopy: Every 3 months (~$30/filter)
Second Shower's subscription auto-ships replacement filters so you never run low. Cancel or adjust frequency anytime.
Ready to Stop Chlorine Damage?
99.9% chlorine removal — NSF certified, independently tested, guaranteed for the filter's entire lifespan.
Shop Showerhead Shop ShowerhandFrequently Asked Questions
Do I really need a shower filter?
If your water comes from a municipal supply (city water), it contains chlorine or chloramine by law — typically 0.2–4.0 ppm. While this keeps the water safe to drink, chlorine is a strong oxidizer that damages the skin's lipid barrier and hair protein bonds with every shower.
For people with eczema, psoriasis, or sensitive skin, removing chlorine can significantly reduce irritation, dryness, and flare-ups. Even if you don't have a diagnosed skin condition, chlorine contributes to dry hair, brittle ends, and color fading.
If you're on well water, you likely don't need a filter (unless your well is chlorinated). You can test your water with a free chlorine test strip — if it reads above 0.5 ppm, a shower filter will help.
Will a shower filter help with hard water spots on glass?
No. Hard water spots are mineral deposits (calcium carbonate, magnesium carbonate) that form when water evaporates on glass, tile, or fixtures. A shower filter removes chlorine and chloramine — not hardness minerals.
If you want to prevent hard water spots, you'd need a whole-home water softener (ion-exchange system) installed at your main water line. However, as noted above, hard water minerals aren't harmful to your skin or hair — the SWET trial found no eczema benefit from removing them.
Second Shower doesn't remove hardness by design, because hardness isn't the problem. We target chlorine — the actual irritant. For more detail, see our guide on shower filters and hard water.
How long does the filter last?
Second Shower filters last 3–6 months for the Showerhand (depending on household size and usage) and 4–6 months for the Showerhead. The exact replacement interval depends on your chlorine concentration and daily shower minutes.
Unlike KDF filters, which degrade in performance after 60 days, Second Shower maintains 99.9% chlorine removal throughout the filter's rated lifespan — verified by independent lab testing on the full assembled unit.
We include a filter-change reminder card with every order, and our subscription service auto-ships replacements on your schedule (cancel or adjust anytime).
Can I use this with a handheld showerhead?
Yes — Second Shower makes both a wall-mount Showerhead and a handheld Showerhand. The Showerhand includes a 60-inch stainless steel hose and mounts to your existing shower arm. It's ideal for washing kids, pets, or seated showering.
Both models use the same Vitamin C filter technology and deliver the same 99.9% chlorine removal with zero pressure loss. The Showerhand uses 128 micro-jets; the Showerhead uses 176.
Does it remove fluoride?
No. Fluoride is added to municipal water (typically 0.7–1.2 ppm) for dental health. It's chemically stable and not removed by Vitamin C, KDF, or activated carbon at shower temperatures and contact times.
Removing fluoride requires reverse osmosis or activated alumina — technologies that only work under pressure in a point-of-use system (like an under-sink filter), not in a shower where water flow is fast and unpressurized.
Good news: fluoride in shower water doesn't affect your skin or hair. It's only beneficial (or controversial, depending on your stance) when ingested. Second Shower targets the compounds that actually matter in the shower — chlorine and chloramine.
Will this lower my water pressure?
No. Second Shower's micro-jet technology (128 jets in the Showerhand, 176 in the Showerhead) maintains full pressure without restrictors or adapters. The filter cartridge sits inline but doesn't impede flow.
KDF and carbon filters, by contrast, force water through densely packed media beds, which creates backpressure and reduces flow by 20–40%. If you've ever used a competitor filter and noticed weak pressure, that's why.
Second Shower's Vitamin C gel matrix has a more open structure — water flows through it easily while still achieving 99.9% chlorine contact and removal.
The Bottom Line
If you have eczema, psoriasis, or chronically dry skin, removing chlorine from your shower is one of the highest-leverage interventions you can make — more impactful than most topical treatments.
Second Shower is the only Vitamin C shower filter with NSF certification at 99.9% chlorine removal that never degrades. KDF filters (Jolie, AquaBliss) start strong but drop below 10% effectiveness by day 60, leaving you exposed to chlorine for most of each filter's lifespan.
Vitamin C neutralizes chlorine on contact, maintains performance for the filter's entire rated life, and adds skin-nourishing vitamins (C, E, B3, B5, B7) — all with zero pressure loss and tool-free installation.
Choose the filter that works as well on day 90 as it does on day 1.
Ready to Stop Chlorine Damage?
99.9% chlorine removal — NSF certified, independently tested, guaranteed for the filter's entire lifespan.
Shop Showerhead Shop Showerhand
Leave a comment
All comments are moderated before being published.
This site is protected by hCaptcha and the hCaptcha Privacy Policy and Terms of Service apply.