Shower filter against limescale: how does it work and which one fits?

You only cleaned the shower screen yesterday – and today the white marks are back already. The shower head sputters, and one jet shoots sideways at the wall. Anyone living in a hard-water area knows this all too well. The reason is limescale in the tap water.

In many regions tap water is hard. The result in the bathroom: white marks on tiles and glass, scaled shower heads and taps. An anti-limescale shower filter works directly at the shower.

How hard is my water?

Your local water supplier publishes the hardness, usually on its website. In Germany, water is classed as soft below 8.4 °dH, medium 8.4–14 °dH and hard above 14 °dH. From “medium” upwards an anti-limescale filter is particularly worthwhile.

Quick test without a meter: is your kettle white inside after just a few weeks? Do drops leave white spots on dark tiles? Then you most likely have medium to hard water.

How the filter works

The Smarald® DF-007 shower filter contains a cartridge with ion-exchange resin. In the resin, the hardness minerals calcium and magnesium are exchanged for sodium. The shower water therefore contains less limescale, and fewer deposits form on the shower head, taps and tiles. How long a cartridge lasts depends on water hardness and consumption.

Think of the resin as a sponge that holds on to the limescale building blocks. At some point the sponge is full – then it is time for a new cartridge.

Installed in two minutes

1. Unscrew the shower hose from the tap.
2. Screw the filter onto the tap with its 1/2" thread – hand-tight, no tools.
3. Screw the shower hose onto the filter.
4. Let the water run briefly – done.

The filter fits all taps and hoses with the standard 1/2" connection.

When to change?

We recommend changing the cartridge after 6 months at the latest (or after approx. 8,000 litres). With very hard water or many people in the household, an earlier change can make sense. Matching cartridge: anti-limescale replacement cartridge DF007-EK01.

How you can tell: the white marks come back although you are doing nothing differently. Then the cartridge is exhausted.

The most common mistakes

• Forgetting the washer. Every threaded joint needs a washer – without it, the thread will drip.
• Tightening with pliers. Hand-tight is enough. Too much force can damage the thread and the washer.
• Forgetting to change it. An exhausted cartridge no longer holds back limescale. Put the installation date straight into your phone calendar.

Good to know

• A shower filter does not replace a whole-house water softener – it only works at the shower.
• Spray plates with silicone nozzles are easy to clear of limescale with your finger.

Matching products in our shop: DF-007 anti-limescale shower filter, DF007-EK01 replacement cartridge, silicone nub shower plate.

In short: check the hardness with your water supplier – from about 8.4 °dH an anti-limescale shower filter is worthwhile. Installation takes two minutes and needs no tools; replace the cartridge after 6 months at the latest.