20 Inch Big Blue Sediment Cartridge, 5 Micron, 3-Pack
Housing one, three changes running.
Three of the 5 micron melt-blown cartridges for the first housing of the AquaGuard or any 20 inch Big Blue unit. On borehole, tank and old-pipe supplies the sediment stage fills first and gets changed on its own between full services; three on the shelf cover a year and a half of that, or a pre-filter housing ahead of the unit.
Why three of the same
The sediment stage is the one that does the heavy lifting and the one that fills first. On a clean municipal supply it lasts the six months with the rest of the set. On a borehole, a tank, or a street with old mains it can be brown in three, while the carbon block behind it is fine. Changing the sediment cartridge alone, in between full services, is the cheap way to keep the pressure up, and it only happens on time if the spare is already in the cupboard.
When to change it
When the shower slows, at six months, or at 0.7 bar of drop if gauges are fitted. If it is brown at three months, fit a coarser 20 or 50 micron stage ahead of the unit and these will last.
