Eheim Filter Media

[CubanCorona]

I recently purchased an Eheim Classic Canister. I had planned on using activated carbon in it, but it came with some unfamiliar media--light beige spheres, slightly smaller than marbles, with a rough texture.

What is this? How often does it need to be changed? When medications require carbon removal, is this media included?

 

[smurfyy_2k3]

carbon is only really to remove access chemical's and if you arent putting any in chances are there not there, the balls you describe are bioballs and they host the bacteria much like a sponge the dot really ever need changing and you can just give em a rinse in some old tank water