20 Inch Big Blue Sediment Cartridge, 5 Micron
Housing one. The coarse load, at whole-house flow.
Melt-blown polypropylene, 20 by 4.5 inch, rated 5 micron, for the first housing of the AquaGuard or any Big Blue unit. Rust, sand and mud from the main, or the silt from a borehole, stop here before they reach the carbon. On dirty supplies buy two and keep one on the shelf.
What it does
A 5 micron sieve with the depth to hold a whole house's worth of grit for months. Melt-blown polypropylene is graded: coarser fibres on the outside catch the big particles, finer fibres inside catch the rest, so it loads evenly instead of blinding on the surface.
When to change it
When the shower slows, at six months, or at 0.7 bar of drop if gauges are fitted. It is the cartridge that fills first. If it is brown at three months, fit a coarser 20 or 50 micron stage ahead of the unit and this one will last.
