Water Purifier Spare-Aquaphos-Siliphos filter To be changed every 24 months Price: £27.60 incVAT By reducing the amount of limescale that builds up on heating elements and the internal parts of appliances, their life is extended, energy costs are reduced as they are more efficient and maintenance is kept to a minimum. The Siliphos filter treats the water to prevent the limescale being able to build-up on surfaces. Only to be used with the Aquaphos BP IN STOCK NOW. FREE MAINLAND UK DELIVERY IN 2-3 WORKING DAYS.