Practical guide

How to improve and treat your tap water

In France, tap water is one of the most closely monitored food products: more than 300,000 samples are taken every year by the Regional Health Agencies. In the vast majority of municipalities it complies with regulatory limits and can be drunk with no additional treatment.

Wanting to "treat" your water is therefore rarely a health issue. It is usually about comfort: a strong chlorine taste, limescale damaging household appliances, or an old plumbing network of unknown condition. This guide explains, without alarmism, when equipment is genuinely useful, and when it is not.

InfoEau sells no equipment. Our comparisons and diagnostics rely solely on public data (French Ministry of Health, Anses, Hub'Eau) and are never influenced by commercial interests.

Why treat your water?

The chlorine taste

Chlorine is added deliberately to guarantee the absence of bacteria all the way to your tap. It is harmless at the doses used, but its taste and smell can be unpleasant. Simply leaving a jug in the fridge for an hour is often enough for it to disappear.

Removing the chlorine taste from water

Limescale (hard water)

Limescale comes from naturally dissolved calcium and magnesium. It is not a health hazard, it is even a useful mineral intake, but it scales up pipes, kettles and water heaters, and can dry out the skin.

Water too hard: what can you do?

Nitrates

Mainly of agricultural origin, nitrates are monitored with a regulatory limit of 50 mg/L. Exceedances are rare and localised, mostly in intensive farming areas. Particular care applies to infants and pregnant women.

Nitrates in water: solutions

Lead in older networks

Public lead pipes have been removed, but indoor connections remain in some buildings built before 1950. The limit is 10 µg/L. Letting the water run for a few dozen seconds after long stagnation greatly reduces exposure.

Lead in water: what can you do?

The solutions, compared

No single device treats everything. Each technology addresses a specific problem, with running costs and limits you should know before buying.

The filter pitcher

What it treats
Chlorine taste, some metals and certain micropollutants depending on the cartridge.
Who it is relevant for
Households bothered only by taste, with drinking-water use only.
Limits
Does not durably remove limescale, nor nitrates. Cartridges must be replaced strictly on time to avoid bacterial growth.

The faucet filter

What it treats
Chlorine, tastes and odours, particles; some activated-carbon models also retain lead.
Who it is relevant for
Households wanting to filter larger volumes without handling a pitcher.
Limits
Reduced flow, regular maintenance, and highly variable performance depending on models and certifications.

Reverse osmosis

What it treats
Almost all dissolved substances: nitrates, pesticides, metals, mineral salts.
Who it is relevant for
Documented cases of persistent regulatory exceedance.
Limits
Expensive installation, significant water rejection, and removal of useful minerals. Rarely justified on a compliant network.

The water softener

What it treats
Hardness only: it exchanges calcium and magnesium for sodium.
Who it is relevant for
Very hard water areas (> 30 °f) where scaling genuinely damages equipment.
Limits
Improves neither health quality nor taste, increases sodium, and requires rigorous maintenance. Keeping one unsoftened tap for drinking is advised.

What if your water is already good?

If your municipality's analyses are compliant and the taste does not bother you, no equipment is needed. This is the most common case in France. Buying a filter "just in case" adds cost and maintenance with no measurable benefit.

How to know what you need

The right approach is to start from real data, not from an impression. InfoEau publishes, for each municipality, the official monitoring results: nitrates, pesticides, hardness, metals, overall compliance.

First check your municipality page, then the personalised diagnosis which cross-references your profile (infant, pregnancy, low-sodium diet) with your water composition.

Bottled water or filtration: the cost

Tap water costs about €0.004/L on average, versus €0.20 to €0.60/L for bottled water, a ratio of roughly 1 to 100. A filter pitcher adds a few cents per litre for cartridges, which remains far below bottled water.

Frequently asked questions