10 Inch Sediment Filter, 5 Micron
Stage one. Sand, rust and silt, before they reach the carbon.
Melt-blown polypropylene, 10 by 2.5 inch, rated 5 micron. Fits the AquaShield and every standard 10 inch housing. The cheapest cartridge in the system and the one that protects the other five, so change it every 6 months without thinking about it.
What it does
A mechanical sieve. Anything larger than 5 micron, which is about a fiftieth of a human hair, stays in the fibres: sand from a pipe repair, rust flakes from an old main, the silt that turns a housing brown. Nothing chemical happens here; that is the next two stages.
When to change it
Every 6 months on municipal water, and immediately if the housing looks brown or the tank takes noticeably longer to fill. A blocked sediment stage starves the membrane of pressure, and a torn one passes grit to the carbon block. Both cost more than a R39 cartridge.
Fitting
Close the feed valve, open the tap to drop the pressure, unscrew housing one with the spanner, swap the cartridge (there is no top or bottom), hand-tighten, open the feed and check for drips. Flush for two minutes. Five minutes, start to finish.
