Chlorine in shower water: what it is for and what a filter head does

Why the water has chlorine in it

If you can smell a hint of pool when the shower runs, that is usually the disinfectant your water utility adds on purpose.

Utilities add disinfectants, such as chlorine or chloramine, to tap water to kill germs and make it safe to drink.

Centers for Disease Control and Prevention, About Water Disinfection with Chlorine and Chloramine. Read 28 September 2026.

How much is normal

The amount in treated tap water is small and regulated.

Chlorine or chloramine levels up to 4 milligrams per liter (mg/L), or 4 parts per million (ppm), are considered safe in drinking water.

Centers for Disease Control and Prevention, About Water Disinfection with Chlorine and Chloramine. Read 28 September 2026.

So a filter in a shower head is not about making the water safe. The utility has already done that. It is about how the water feels and smells on skin and hair when you stand in it every day.

What the beads in a FASTRAS handle do

The clear handle holds two kinds of mineral beads, grey and red, and the water runs through them before it reaches the face. They are there to reduce residual chlorine on the way through.

They do not soften hard water. Calcium and magnesium, the minerals that leave white marks on glass, pass through. If your area has hard water, the face of any shower head will need a wipe with a little vinegar now and then.

Keeping the handle clear

• Look at the handle every few weeks. The beads should look loose, not packed into a solid block.
• If the flow drops, check the washer at the hose end for grit before anything else.
• Wipe the face with a soft cloth. The small holes clog faster in hard water.