20 Inch Refillable Cartridge Shell
Fill it with siliphos and the scale stops. Refill it, do not replace it.
An empty, refillable 20 by 4.5 inch shell with screw caps and a mesh screen at each end. Fill it with up to 4 kg of siliphos balls and it fits any Big Blue housing as a scale and corrosion stage for the geyser and the appliances. When the balls are a third gone, top it up; the shell lasts for years.
How siliphos works
Siliphos is a food-grade polyphosphate that dissolves at 2 to 3 grams per cubic metre of water. At that dose it lays a molecular film on the inside of pipes, geysers and appliances that stops scale forming and stops rust. It is not a softener: the calcium and magnesium stay in the water, so it still tastes right and the geyser still stops scaling.
Where it goes
In any 20 inch Big Blue housing, after the sediment stage: the third housing of an AquaGuard in place of the 1 micron cartridge, or a single housing of its own on the geyser feed. Water flows in through the bottom screen, over the balls, and out through the top.
Refilling
Unscrew the top cap, pour in siliphos balls to two-thirds full (about 4 kg for a full charge), cap, fit. Check every three months; when a third has dissolved, top it up. A household uses 1 to 2 kg a year.
Before you buy.
Goes with it.
Whole shop
Siliphos Balls, 1 kg
Stops scale and rust without softening. A gram or two per cubic metre.
20 Inch Big Blue Housing with Bracket
One housing, bracket and spanner. The building block.
Free courierAquaGuard Whole-House Filter
Every tap, every shower, every appliance. On a stainless steel frame.