<a href=showthread.php?s=&postid=10402903#post10402903 target=_blank>Originally posted</a> by XSiVE If you want to keep nitrates from building up too high, you can clean 10% of them or so with each weekly water change.
I would be more concerned about making sure that sponges and pads are clean and kept clean on a regular basis. That is where most of your nitrates will come from.
Bioballs are supposed to be media that harvests the bacteria that will turn ammonia into nitrites and then nitrates. I would not clean them unless you really see some detritus. Maybe take them out and rinse them with salt water to remove some of the big detritus particles but that is about it.