Sodium silicate is used as an alum coagulant and an iron deflocculant in water treatment plants in municipal water supplies. Sodium silicate binds to colloidal molecules, creating larger aggregates that sink to the bottom of the water column. The microscopic negatively charged particles suspended in water interact with sodium silicate. Their electrical double layer collapses due to the increase of ionic strength caused by the addition of sodium silicate (doubly negatively charged anion accompanied by two sodium cations) and they subsequently aggregate. What this means, is that your softener or iron filter does not recognize the molecules and it ‘masks‘ the silicate, allowing it to pass through undetected, creating staining even though your equipment is working properly.
The solution is a Silicate filtering system. It can be a stand-alone unit or combined with softening resin and carbon, providing filtering capabilities a standard water softener or iron filter cannot perform.
