The ceramic media in your biorb forms the main part of filtration and is important in keeping the water clear and healthy.
Beneficial bacteria colonise the ceramic media and remove toxic fish waste from the water as the water flows through it. Biorb ceramic media is full of pores for bacteria to live on, just 900g of ceramic media has the surface area equivalent to a football pitch.
You can add more media to your biorb to increase the area for filtration.
Over time, these pores can become blocked with dirt and limescale reducing the surface area available. Replacing some of the media every year or so can help to keep the filtration efficient.
Never replace more than 1/3rd of your media at one time and wait at least a month before replacing any more.
Ceramic Media is a man made material with a massive surface area for housing beneficial bacteria which activates the biological filtration within your aquarium.
Adding more increases the surface area available for bacteria colonisation which enhances biological filtration.
Ceramic media will not alter the water pH.