These cartridges can be refilled numerous times and the refilling process is simple. Used primarily to house DI resin, using refillable cartridges is a much more economical solution compared to buying standard ready-to-use water filter cartridges.
It is important to ensure that you pack the resin as tight as possible. This can be easily achieved by tapping the cartridge on a firm surface as you are packing it and before sealing it. This will eliminate the chance of channelling after the cartridge has been installed which would allow water to pass through without being filtered.