Water softening apparatus; parts for water purification apparatus, namely, polyphosphate dispensers, polyphosphate and silicate dispensers; polyphosphate dispensers with filters for the treatment of water; parts for water purification apparatus, namely, replacement cartridges for polyphosphate dispensers; water filters for use in central heating systems; water treatment filters; water filter cartridge units in the nature of water filtering units for domestic use, water filtration and purifica...