Hmmm what more really needs to be said.  Well Ceramic rings for the nano cube should be changed.  Good bacteria breeds on the pores of the rings.  This hels keep in check many of the "Bad things" That start up when you have fish waste.

Be sure you do not change this the same time you change bio- balls, sponges, or the carbon of your nano cube.  If you do you could remove to much of the positive bacteria in the tank and have rising levels of ammonia and such.

If you have any questions on the jbj replacement nano cube ceramic rings feel free to shoot us an email.