Why We Care About Test Results

Most shower-filter brands talk about what their products claim to do. We became more interested in what could actually be measured, and in who did the measuring.

A category built on claims

Shower filters sit in an unusual space between water treatment, wellness and personal care. Many brands promise chlorine reduction, softer skin, healthier hair or a better shower. In many markets, though, the testing conditions behind those promises are hard to find, and harder still to compare or verify.

So marketing claims are common and transparent performance data is rare. We wanted to work the other way round.

Why Korea matters

PICKI NIKI is engineered in Germany for European hard-water conditions, but developed, manufactured and tested in Korea. There is a reason for that.

Korea has become one of the world's most mature shower-filtration markets. As filtered shower heads became mainstream, consumers, media and regulators began asking a simple question: do these products actually do what they claim?

The 2021 wake-up call

In November 2021, the Korea Consumer Agency tested 20 filter shower heads sold online. Seven of the 20 fell short of the basic performance bar, removing less than 80% of residual chlorine. Six of those seven were being sold with no supporting evidence for their chlorine-removal claims at all, and some carried "100% removal" language while failing the agency's test.¹

The issue was not whether shower filters existed. The issue was whether brands could prove what they advertised.

That shaped how we chose a manufacturing partner. We were not looking for the lowest-cost supplier. We were looking for a partner with a proven filtration track record in one of the world's most scrutinised shower-filtration markets. Korea was a more expensive manufacturing option. It was also the option we trusted most.

Evidence before marketing

That experience still shapes how we think about product claims. A claim on its own is easy to make, and we don't think anyone should have to rely on marketing language alone.

Many shower filters advertise high chlorine-removal figures, often 95 to 99%. The number is rarely the problem; what stands behind it is. A percentage means little without the conditions that produced it: which laboratory ran the test, whether that laboratory is recognised and whether the report was issued under its accreditation, and the flow rate and filter life the test used.

Water-filtration tests are often run under cool, controlled, low-flow conditions. A shower delivers water fast and hot, so a figure from standard test conditions does not automatically transfer to the shower. That applies to our own chlorine test as well, which is why we state its conditions below.

Two questions therefore matter more than the headline number. Who carried out the test, and were its conditions defined and reported? We care less about how high a number is than about whether it can be traced back to a defined test.

That is why we keep prioritising:

• Testing by named laboratories
• Recognised testing institutions
• Clearly defined testing conditions
• Transparent reporting, including each report's accreditation status

Our filter has been tested at three named Korean laboratories. None of these test reports was issued under KOLAS / ISO 17025 accreditation, and certificate references are available on request. Here is what each test shows, and under which conditions.

When we say free chlorine was reduced to non-detectable at the outlet, we can point to a 2020 test by KEWI, the Korea Environment and Water Works Institute. KEWI is a government-designated drinking-water testing institute and is not KOLAS / ISO 17025 accredited. It measured free chlorine falling from 0.19 mg/L to non-detectable over 100 litres at 2.52 L/min and 22 °C. That flow is about a third of the real shower flow KTR measured (7.5 L/min), and "non-detectable" states no detection limit, so no percentage can be derived from it.

When we say our vitamin C stage neutralises alkaline water, we can point to a commissioned test at KTR, the Korea Testing & Research Institute.² KTR is KOLAS / ISO 17025 accredited as an institution, but this pH report was issued as a contract test outside that accredited scope. At 7.5 L/min, alkaline test water was neutralised from pH 9.0 to 6.45 and from pH 10.0 to 7.38. The test water was NaOH-adjusted soft water, so the results do not transfer one to one to hard tap water.

When we refer to skin compatibility, we can point to a clinical patch test at the P&K Skin Clinical Research Centre in Seoul. The vitamin C filter material was confirmed non-irritant, with a Skin Irritation Index of 0.03 (n=30, 2023). P&K tested according to the MFDS guideline and its own protocol, and the report claims no accreditation.

Better shower water should not depend on marketing claims alone. It should be supported by evidence you can check.