Engineered for the real conditions of a shower - hot & hard water, fast flow, chlorine. Tested in independent Korean laboratories.
Explore the System ↓
Most filtration systems were originally designed for drinking water - slow flow, cool temperature, long contact time. A shower is the opposite: fast, hot, continuous, high volume. What works for slow, cold drinking water doesn't behave the same way in a fast, hot shower.
That's why PICKI NIKI is designed specifically for real shower conditions.
Two stages, each with a specific role. Designed to be used together - not separately.
Removes rust, particles and pipe debris, regardless of flow rate or temperature. Hot water accelerates the release of rust and debris from old pipes - 5μm melt-blown cartridge in sealed full-flow housing, 100% pass-through, no bypass.
A high-concentration Vitamin C formula that neutralises chlorine on contact and forms soluble complexes with calcium and magnesium minerals. Reacts directly with chlorine on contact - even in fast-flowing water. More active in warm water - suited to hot showers.
Chlorine and physical impurities need different filtration approaches; using only one leaves part of the problem unresolved.
Designed to be used together - not separately.
Four everyday changes after switching to filtered shower water.
Skin feels softer and less dry.
Easier to manage, less mineral residue.
Fewer mineral marks on skin and hair.
Strong, consistent flow, gentle on skin.
Chlorine neutralisation: C₆H₈O₆ + HOCl → C₆H₆O₆ + HCl + H₂O. Ascorbic acid (Vitamin C) reacts with free chlorine, converting it into harmless by-products - the same established principle used in pool-water treatment.
⁴ KTR pH-stability test (2023). ⁵ KEWI chlorine test (2020).
Carbon and KDF filters work by physical adsorption - water has to stay in contact long enough. A shower gives them almost no time. Vitamin C reacts directly with chlorine on contact, and faster in warm water.
| PICKI NIKI (Vitamin C) PICKI NIKI1 cartridge ~ 250 lemons of Vitamin C | Carbon filters Adsorbent media | KDF filters Zinc/copper redox | Mineral / Ceramic Beads No published mechanism | |
|---|---|---|---|---|
| How it removes chlorine | Reacts on contact (redox) | Physical adsorption - needs contact time | Redox media - needs contact time | No published chlorine mechanism |
| In a real shower (fast flow, short contact, hot water) | Reacts on contact, faster in warm water | Designed for slow, cool drinking water; capacity consumed as it works | Manufacturer data: ~90% removal at shower flow vs >98% at slow flow | Often rebranded under proprietary names |
| Contact time needed | ~0.1 secAt full shower flow | 25-40 secEBCT required (WQA standard) | SecondsAt low flow only | n/a |
Activated-carbon filters remove chlorine by trapping it in a porous bed. That same bed - porous, nutrient-rich, and stripped of chlorine's antibacterial effect - can become more susceptible to biofilm formation over time. Peer-reviewed studies of carbon point-of-use filters have measured heterotrophic bacteria rising to many times the incoming level as the filter ages⁷ ⁸.
⁷ Carbon biofilm peer-reviewed: Environmental Science: Water Research & Technology (RSC, 2017). ⁸ Carbon bacterial growth: PubMed 6784673.
Many shower filters have no dedicated stage for the rust, grit and pipe debris that hot water pulls out of old plumbing. PICKI NIKI's Step 1 sediment filter is built for exactly this. Because it's physical capture - not a reaction or timed adsorption - it works regardless of flow rate or temperature.
| Feature | PICKI NIKI | Carbon / KDF filters | |
|---|---|---|---|
| Dedicated sediment stage | |||
| Particle capture (5μm melt-blown, all water forced through) |
Sources for individual claims, marked with footnote numbers. Peer-reviewed papers are cited in support of underlying mechanisms, not as proof of product efficacy.
Drinking-water filter context. Most domestic filters originally designed for slow flow, cool temperature, long contact time. Sources: Wu et al., npj Clean Water (2021); WC&P Online (industry) - NSF/ANSI 42 carbon cartridge EBCT.
Activated carbon - mechanism + contact time. Wu et al., npj Clean Water (2021); WC&P Online (industry) - NSF/ANSI 42 carbon cartridge EBCT approx 0.14 min in test protocol; Aqueous Chlorine/Activated Carbon Interactions, Journal of Environmental Engineering 110(3), 1984 - chlorine reduction on the carbon surface significantly decreases the carbon's adsorption capacity.
KDF data. Kymera International, KDF-55/85 Process Media Technical Bulletin (2023) - approx 90% in shower water filters due to high flow rate vs more than 98% in slow home systems.
KTR pH testing. Korea Testing & Research Institute contract test, flow 7.5 L/min, 2023. Input pH 10.0 reduced to 7.38; input pH 9.0 reduced to 6.45. (Claims library: C220)
KEWI chlorine testing. Korea Environment and Water Works Institute, 2020. 0.19 mg/L free chlorine reduced to non-detectable at 2.52 L/min, 22°C. (Claims library: C035)
Carbon biofilm (peer-reviewed). Environmental Science: Water Research & Technology (RSC, 2017) - activated-carbon-block POU filters; effluent heterotrophic plate counts plateaued up to approx 100x influent counts after approx 85% of rated volume. Drinking-water POU filters, general mechanism.
Carbon bacterial growth (peer-reviewed). PubMed 6784673 - three activated-carbon POU filters removed free chlorine below detection, but standard plate-count bacteria in effluent rose steadily and stayed elevated over 8 weeks.
Dermatological test. P&K Skin Clinical Research Centre, Seoul, n=30, 24h patch test, supervised by dermatology professor at Chung-Ang University Medical Center, 2023. Skin Irritation Index 0.03 (non-irritant). (Claims library: C072)
Atopy certification. World Atopy Association, 2025-2027. (Claims library: C221)
RoHS materials test. Filter-material (not water) test confirming lead, mercury, cadmium and hexavalent chromium below RoHS limits. A materials-safety result, NOT a claim that the filter removes heavy metals from water.
ISO manufacturing. ISO 9001:2015 (quality), 14001:2015 (environment), 37001 (anti-bribery), 37301 (compliance), 45001 (occupational H&S) - issued by ICR Ltd., valid through 2028-09-15. (Claims library: C222)
