Replacement Water Filter Cartridge for the Kinetico AquaScale (9000) Drinking Water Filter. Handy indicators which tell you when to change your cartridge, but we recommend approximately every 9-12 months. This is however dependent on your exact water usage. All Kinetico cartridges are simple to replace. Price quoted includes VAT. Local delivery is free. UK mainland delivery is £8.00 and usually arrives within 5 working days.