Choosing the Best Reverse Osmosis System

Quality Water Starts Here

At NZ Pump & Water Filters, we believe in quality over the lowest price. Some systems cost as little as $400—but without NSF/ANSI 58 certification, there’s no guarantee they truly purify water.

We stock trusted, certified brands—Pentair, Atlas Filtri, Ecosoft, and Hydronix—so you can enjoy genuine RO water with the best materials and results.

Domestic Tanked Systems

Our tanked RO systems store around 4 litres of purified water and produce 80–90 litres per day, depending on water quality.

• Pressure-boosted options: Maintain ~40 psi for homes with low water pressure.

• Ecosoft tankless systems: Perfect for higher water demand, including commercial use—or home use if budget allows.

Note: Even if other brands claim “more on-demand water,” this is the realistic maximum output.

How RO Systems Work

RO systems use prefilters to clean water like a standard undersink filter, then pass water through the RO membrane, the most reliable purification method available.

• Standard filters: 0.5–1 µm

• NSF/ANSI 58 RO membranes: 0.0001 µm

This removes microplastics, PFAS (“forever chemicals”), heavy metals, salts, and chemicals, giving you water that’s virtually contaminant-free—far better than bottled water.

Our Top Pick: Pentair GRO 2550

• Recovery Rate: 50% (1:1 purified-to-waste ratio)

• Optional Mineral Filter: Add if desired, still cheaper than premium alternatives

• Filter Replacement (24 months): ~$370 (~$0.50/day)

Water Costs Example:

• 4-person family drinking 2 L/day (~2,900 L/year)

• Waste water cost ≈ $10.73/year

Efficient, reliable, and easy to maintain—our #1 recommendation.

Best Seller: Oasis DP 6-Stage RO

• Features: Remineraliser and extra prefilter included

• Origin: Designed in Italy, partially made in Italy

• Filter Replacement (24 months): ~$800 (~$1.08/day)

Cost Comparison (Family of 4):

Savings: Choosing the Pentair system saves $33/year in water costs.