How to Choose a Whole House Water Filter Cartridge
July 04, 20212 min read
Choosing the right cartridge for your whole house filter is straightforward once you understand the main types and what each one does. Here’s a practical guide.
The first stage in any whole house system. Removes sand, silt, rust, and particles. Available in polyspun (melt-blown) and pleated polyester formats:
Polyspun (melt-blown): depth filtration — traps particles throughout the cartridge body. Higher dirt-holding capacity. Cannot be cleaned and reused.
Pleated polyester: surface filtration — traps particles on the pleated surface. Can be rinsed and reused a limited number of times. Better flow rate at equivalent micron ratings.
For most Australian town water supplies, a 5–10 micron sediment cartridge is the right starting point. For high-sediment bore or tank water, start with a 50-micron pre-filter followed by a 5-micron stage.
Carbon Block Cartridges
The second stage in most whole house systems. Removes chlorine, chloramines, VOCs, pesticides, and taste/odour compounds through adsorption. Carbon block cartridges provide better contaminant removal than granular activated carbon (GAC) at equivalent flow rates because the compressed block forces water into contact with more carbon surface area.
Dual-Grade Depth Cartridges
Combines coarse and fine filtration in a single cartridge — typically 25 micron on the outside grading down to 1 micron at the core. Effective for water with a wide range of particle sizes. Removes more sediment than a single-grade cartridge without the same pressure drop.
Choosing the Right Micron Rating
Lower micron ratings filter finer particles but reduce flow rate and require more frequent replacement. For most Australian town water households:
Stage 1 (sediment): 5–10 micron polyspun or pleated
Stage 2 (carbon): 5 micron carbon block
Use a lower micron rating (1–5 micron) only if your water has very fine sediment, iron, or you’re filtering bore/tank water.
Replacement Intervals
Sediment cartridge: every 2–6 months (replace sooner if pressure drops)
Carbon cartridge: every 4–6 months (replace sooner if chlorine taste returns)
Can I use any brand of cartridge in my Big Blue housing?
Yes — any standard 4.5" x 10" cartridge fits a Big Blue housing regardless of brand. Match the cartridge type (sediment, carbon, etc.) to your filtration needs. Browse our replacement cartridge range.
Can I reuse a sediment cartridge?
Pleated polyester cartridges can be rinsed and reused a limited number of times. Polyspun (melt-blown) cartridges should not be reused — the fibres can tear and allow sediment through. Carbon cartridges cannot be regenerated and must be replaced.
