Is a water filter worth it? Cost analysis of bottles vs filtration

Tap water vs bottled water — standards and realities in Poland

In Poland, drinking water from the network is subject to EU regulations (Directive (EU) 2020/2184) and national laws. This means constant quality supervision and regular testing of parameters.microbiological and chemical. In most Polish cities, you can drink water directly from the tap or after simple filtration to improve taste and smell. Bottled water meets similar safety standards, but it is a packaged product, which generates additional costs and has a significant environmental impact.

In short: safety standards fortap water and bottled water are comparable, and a water filter improves comfort (taste, smell) and helps reduce plastic.

Key thought: In Polish conditions, "tap + reasonable filtration" combines safety with convenience and low cost per liter, meeting the highest water quality standards.

How much does a liter of water really cost?(tap water, bottle, filter)

Let's calculate the cost of a liter in typical scenarios. Assumptions for comparison: a family of 4, recommended fluid intake ~2 L/person/day (including drinking water) — a total of ~8 L/day ≈ 2,920 L/year. Below are the approximate costs per liter in 2024/2025 in Poland:

• Tap water (Warsaw — just water, excluding sewage): approx. 0.0059zł/L. Annually for 2,920 L is ~17.23 zł for the raw water itself.
• Bottled water (1–2 zł/L according to retail prices): ~3,500–5,800 zł/year for a family of 4 (at 2,920 L). Result depends on brand and promotions.
• Filtering pitcher + cartridges(performance 150 L/cartridge): the cost per liter depends on the price of the cartridge. Example: cartridge 19–25 PLN ⇒ ~0.13–0.17 PLN/L. For 2,920 L, the cost is around ~380–500 PLN/year.
• Kitchen/RO filters under the sink (depending on the model): annual pre and post filters usually ~150–350 PLN, RO membrane every 2–5 years (cost spread annually)*.The actual cost of a liter is approximately ~0.06–0.15 zł/L with family consumption. The drainage ratio (water to drain) in modern RO systems can be 1:1–1:2, which raises the cost by several to a dozen zł per year (minimal impact).

*For example: pre-filters 6–12 months, mineralizer 12 months, membrane 2–3 years. Actual prices depend ona specific set and quality of incoming water.

Cost conclusion: even with low consumption water filtration is usually ~10–30× cheaper than bottled water. The difference increases with the number of household members and activity (more liters = lower unit cost of the filter).

It's worth remembering: Bottle: ok. 1–2 zł/L. Jug/kitchen filters/RO: usually ~0.06–0.17 zł/L. Tap (without filtration): ~0.006 zł/L — but the filter improves quality, taste, and comfort.

Filter operating costs — real ranges

To accurately calculate the cost of the water filter,we take into account the family size, water hardness, and service schedule.

Filter jugs

• Cartridge performance: most often 150 L (about 30 days with standard use).
• Annually: a family of 4 needs about ~20 cartridges ⇒ approximately ~300–500 PLN/year.

Filtering bottle

• Cartridge performance: often 150 L (replacement every 4–8 weeks with intensive use).
• Cost per liter similar to a jug; plus mobility and no carrying of packs.

Kitchen filters / reverseosmoza(RO)

• Pre-filters (mechanical + carbon): every 6–12 months
• Post-filters (post-carbon, mineralizer): every ~12 months
• RO Membrane: every 2–5 years (with good water quality and service).

CostThe total for a 4-person household is usually ~250–500 PLN/year for maintenance*; with higher consumption (e.g., 10–15 L/day), the cost per liter decreases.

Key takeaway: the lowest cost per liter of water at home comes from a permanent kitchen filter (including RO) for families of 3–6 people; a pitcher and a filtering bottle are great as a start and "mobile support," but they do not provide such high-quality water.

Quality and health: chlorine, microplastics, taste

In Poland, tap water is safe, but water filtration improves taste and smell (reduction of chlorine, fine particles). In bottled water - despite its safety - scientists detect micro and nanoplastics. New measurements have shown hundreds of thousands of nanoplastic particles in 1 liter of bottled water (on the order of~10⁵–10⁶ pieces/L). Additionally, elevated temperature and/or sunlight can intensify the migration of substances from PET packaging (e.g., antimony) and increase the release of microplastics. This is a practical argument for avoiding long storage of packs in heat and for drinking filtered tap water. (which, unfortunately, can often be observed in front of the supermarket)

• Filtering jugs/bottles: reduce chlorine and particles, improve taste; for travel, it's the most convenient way to access drinking water.
• Kitchen filters/RO: besides taste, they lower TDS and a wide range of physicochemical contaminants (bacteria, viruses, microplastics, chlorine, and others)

It's worth remembering:to reduce exposure to microplastics and substances from packaging, it is better to drink water from the tap after filtration than from plastic bottles exposed to sunlight and heat.

Ecology and convenience — water logistics at home

LCA analysis showed that the environmental cost of bottled water can be up to 3,500× higher than tap water (raw materials, energy, waste). There is also logistics involved.carrying packs, home storage, and waste collection. Kitchen filters and jugs generate incomparably less waste (only cartridges) and are transport-neutral.

Conclusion: home filtration is simultaneously cheaper, more convenient and cleaner for the environment.

For whom: jug, filtering bottle, kitchen filter,osmoza

The easiest way to choose a solution that fits your lifestyle and budget:

• Single/student: a pitcher or filtering bottle (+ mobility). Low entry cost.
• Family of 3–6 people.: kitchen filter (e.g., carbon/UF) or reverse osmosis -lowest cost/L, full convenience.
• Minimal intervention in the kitchen: compact under-sink systems with quick service (bayonet cartridges).
• Taste of coffee/tea: carbon filter/carbon block improves aroma, reduces chlorine and volatile compounds.

Key thought: the higher the consumption,that's why it pays off to have a permanent kitchen filter/RO; a pitcher/bottle is a great start or a purely travel option.

How to choose filtration systems and take care of maintenance

Please make your selection based on local water and the needs of household members. The most important data: hardness, iron/manganese (if there is a problem), TDS, number of people, average water consumption permonth.

Do you want to avoid plastic and carrying water? We invite you to our store — we will select filtration systems and service cartridges for your kitchen and water parameters.

Summary

Economically and practically water filtration wins over bottled water. FamilyA 4-person household can save annually approximately 3,000–5,500 PLN compared to buying bottles, while also reducing plastic and the logistics of shopping. In Polish conditions, the best cost/quality balance is provided by a kitchen filter (including RO) — a pitcher and a filtering bottle perfectly complement the set. Check out compact kitchen filters and filtering bottles inin our store: quick installation, easy service, low cost per liter.