you're welcome. In addition, the cartridge has two sections, small and big. Small part is a indicator. You don't need to top up everyday. Ink in the small section stands still, while ink in the big section drops according to usage. When ink in the big section is not visible, then fill it up. If ink is not visible on both section means it is near end i.e reached down to 2cm. You should keep 2-3 spare cartridges or even set of 8 handy. I think it should be 10 bucks per cartridge. Also change it every year. Sometimes it leaks through the rubber plug. One plus of these cartridges you'd be able to see how ink system acts. After a cleaning cycle, all channels' ink level should be down at same rate. If not og-oh.