I have not come across the Emperor filter, but changing filter media every 2 weeks is not good as no time is given for the benificial bacteria to grow. If the carts. do not contain carbon then there is no reason why you shouldn't rinse them in water taken from the tank (not tap water) and continue to use them for many months. If there is more than 1 cartridge then alternate replacement thus keeping a mature filter media for converting nitrites.
If carbon is present then this is only active for around 14 days after which it may start to leach back the impurities it has taken from the water. Maybe it is posible the strip the cartriges remove the carbon and replace with a different material? then it would only need replacing after 4- 6 months!
Steve