Immersable pump with strange pellets?

Question

I have an Hailea HX1000A immersable pump It has a sponge and biofilter. In a small holder under the pump it has these small green pellet looking stuff (it looks almost like the poison for rats Rattex pellets), what is this and does it need 2 be changed?

Answer 1

it could be carbon

if so it will need changing often

Answer 2

Is it a carbon element or a ceramic biomedia?

If it's a carbon element then you change it every month or 2.

If it's a ceramic media it lasts for years. The ceramic media is just a place for bacteria to live, so once you get them established, leave them in place.

Ian