How Shouldit Tests Shower Filters

What It Is

Using water with a high chlorine concentration, we test the shower filter’s ability to reduce or neutralize chlorine. We also compare the total dissolved solids (TDS) levels before and after filtration to determine if the filter adds minerals to the water.

Why It is Important

Chlorine is a common disinfectant in municipal water and is generally used at a safe concentration. However, even at such small concentrations, chlorine in shower water may cause dry and itchy skin in sensitive individuals. In addition, some people find that washing their hair with chlorinated water causes hair breakage and hair loss. Most shower filters claim to reduce or neutralize this chemical.

Minerals, meanwhile, are believed to have the opposite effects on your skin and hair at small concentrations. While we could not find a lot of studies on this, the mineral content in shower water seems important to many consumers, and we conduct this test so you can make an informed decision for yourself.

How We Test

We created a solution with 10 milligram calcium hypochlorite per liter of water, which equals 10 parts per million. This results in a dark green color on the chemical strip test, which indicates an unsafe level of chlorine. This water has a total dissolved solids (TDS) value of 64-65 ppm, measured using a TDS meter. We keep it in a large bucket and pump it through the shower filter.

We then collect the water and use test strips and the TDS meter to determine the total chlorine chlorine level and TDS of the filtered water.

How We Score

We compare the test strip against the color charts on the box and record the chlorine level. A filter that can strip water of chlorine and bring the concentration to 0 parts per million (ppm) scores 10 points, and it loses 1 point for every additional 1 ppm of total chlorine.