It is recommended that you flush your fountain pen with cool, clear water on a monthly basis. The easiest way to flush a pen that has a converter or piston is to draw clear water as you would ink, expel the water, and repeat this until the water coming out of your pen is clear. It is a repetitive process that may take a little while, but it is necessary. You should also do the flush whenever you change ink colors or brands. You can also remove the convertor clean that part on its own by filling and emptying, Then run cool water from the tap through the back of the pen blowing through it until the ink color is gone. Remember to blow dry or air dry the nib section and convertor completely.