Whole House Filter Flow Guide (Big Blue Systems)
Choosing the right filter isn’t just about what it removes — it’s also about maintaining strong water pressure throughout your home.
Below is a simple guide to what each filter type can comfortably handle in a typical household. Browse our Whole House Jumbo Filters collection to find the right fit.
🔹 10" Big Blue Systems (Standard Homes / Lower Demand)
| Filter Type | Best For | Comfortable Flow Rate |
|---|---|---|
| Sediment (20–50µ, pleated) | Dirt, rust, particles | 30–50 L/min |
| Radial Flow Carbon (GAC) | Chlorine, taste, odour | 30–40 L/min |
| Standard Carbon (GAC/KDF) | General chemical reduction | 15–25 L/min |
| Carbon Block (5–10µ) | Finer filtration, better chlorine removal | 8–15 L/min |
| Carbon Block (1µ) | Very fine filtration | 5–10 L/min |
👉 Best suited for: small households, lower simultaneous water use. See our 10" Pleated Sediment Pre-Filter as a starting point.
🔹 20" Big Blue Systems (Family Homes / Higher Demand)
| Filter Type | Best For | Comfortable Flow Rate |
|---|---|---|
| Sediment (20–50µ, pleated) | Dirt, rust, particles | 60–90 L/min |
| Radial Flow Carbon (GAC) | Chlorine, taste, odour | 50–70 L/min |
| Standard Carbon (GAC/KDF) | General chemical reduction | 25–40 L/min |
| Carbon Block (5–10µ) | Finer filtration, better chlorine removal | 15–25 L/min |
| Carbon Block (1µ) | Very fine filtration | 10–20 L/min |
👉 Best suited for: family homes, multiple bathrooms, higher flow demand. Our 20" Pleated Sediment Pre-Filter and Jumbo GAC-KDF55 High Flow Filter are popular choices.
Why Flow Rate Matters
All filters create some restriction. If a system is undersized, you may notice:
- Lower shower pressure
- Slow bath filling
- Reduced flow when multiple taps are used
That’s why we recommend matching the filter size and type to your household demand, not just the contaminants.
Our Recommendation
For most New Zealand homes:
- 20" systems are the best all-round choice
- They provide better pressure, longer lifespan, and more consistent performance
Simple Rule of Thumb
- Want maximum flow & minimal pressure drop? → Go radial carbon or larger filters
- Want finer filtration? → Use carbon block, but size up to 20"
Need Help Choosing?
Every home is different — pipe size, pressure, and water usage all matter. We can recommend the right setup based on your number of bathrooms, household size, water pressure, and what you want removed. Call us on 0800 040 617.
Find Your Whole House Filter
Browse our full range of Big Blue whole house filtration systems — 10" and 20" options for every household size and flow requirement.
Shop Whole House Jumbo Filters →