QTR-Quadtone RIP

I was printing a series of 10 prints and in between each print I did a 
check on the print monitor to see if my "photo black ink" was running 
out (cartridge was almost empty)....although I haven't heard the 
printer performing a "cleaning cycle", I suddenly noticed on the 
monitor that the cyan ink amount had become critical (warning).
...or is it so that you don't hear those cleaning cycles?

Regards,
Herman