- A family of 4 spending $40/week on bottled water: $2,080/year
- Under-sink RO system (installed + 10yr maintenance): $1,100 + $200/yr = $3,100 over 10 years
- Bottled water same family over 10 years: $20,800
- Saving with RO over 10 years: $17,700
- Quality: Quality RO water is typically as good as or better than bottled water — most bottled water is filtered municipal water
- Environment: An Australian family of 4 using bottled water generates ~2,000 plastic bottles per year
The real cost comparison
Bottled water looks cheap per bottle. It looks very different when you calculate annual household spend.
| Scenario | Year 1 | Year 2–10 | 10-Year Total |
|---|---|---|---|
| Family of 4 — bottled water @ $40/wk | $2,080 | $2,080/yr | $20,800 |
| Under-sink RO (installed + maintenance) | $1,300 | $200/yr | $3,100 |
| Under-sink carbon filter | $600 | $120/yr | $1,680 |
| Benchtop gravity filter | $200 | $60/yr | $740 |
An RO system installed at $1,100 with $200/year maintenance costs $1,300 in year one. A family spending $40/week on bottled water spends $2,080 in year one. The RO system pays for itself in under 8 months. Every year after that, the family saves $1,880. Over 10 years, the saving is $17,700. This is before accounting for the environmental benefit of eliminating ~2,000 plastic bottles per year.
Is filtered tap water as good as bottled water?
Most Australian bottled water is filtered municipal (tap) water — often from Sydney, Melbourne, or Brisbane water supplies — that has been further processed and bottled. It is not spring water in most cases, despite packaging that implies otherwise.
A quality reverse osmosis system removes more contaminants than most bottled water treatment processes. RO removes up to 99% of dissolved solids, fluoride, heavy metals, PFAS, chlorine, bacteria, and microplastics. Many bottled water brands use simpler carbon filtration — effective for taste but not for the comprehensive contaminant removal RO provides.
✓ Home RO water
- Up to 99% of contaminants removed
- No microplastics from plastic bottles
- Produced on demand — always fresh
- Cost: ~$0.01–$0.03 per litre
- No BPA or plastic leaching
- Remineralisation stage available
⚠️ Typical bottled water
- Often filtered municipal tap water
- Microplastics detected in 93% of brands tested (Orb Media 2018)
- BPA and phthalate leaching from plastic, especially when heated
- Cost: $0.40–$2.00 per litre
- Inconsistent quality between brands and batches
- Not independently regulated for contaminant removal
Environmental impact
Australia generates approximately 400,000 tonnes of plastic waste from single-use plastic bottles annually. A family of four drinking the recommended 2L per day from bottled water purchases approximately 730 x 1.5L bottles per year — roughly 2,000 bottles if counting smaller individual bottles.
Even with Australian recycling programs, approximately 56% of plastic bottles end up in landfill or the environment. A home water filter eliminates this entirely — the filter cartridge is a fraction of the plastic waste by weight and volume.
When bottled water still makes sense
- Travel and emergencies: When access to your home filter isn't available
- Verified contamination events: During a declared "boil water" notice or known contamination — though at these times, bottled water of known origin is appropriate
- Specific mineral water preferences: Genuine mineral water from a verified spring source has a different mineral profile than RO water — relevant if you have specific mineral intake reasons
Yes. Australian tap water in all major cities meets the Australian Drinking Water Guidelines and is safe to drink unfiltered. The choice between tap, filtered tap, and bottled water is not a safety decision in most Australian cities — it is a taste, quality optimisation, convenience, and cost decision. The case for filtration is strongest for taste improvement and cost savings vs bottled water.