Does anyone know what the blue pebble stuff in the filter is called?


Well-known member
May 23, 2016
Have a cartridge filter in a pod. Above the cartridge is a relatively slender plastic container with black caps on it that has little blue pebble like media in it. The cap came off and all it came out last year. Trying to find some of this stuff to buy and re put in the container in the pod, but I can't seem to find it anywhere because I do not know what it is called. Anyone able to help me out? The blue pebbles were maybe like half the size of peas.

Or is it not even necessary to replace these.