Filtering takes place in different stages:
At the beginning, before the water goes through the further purification process, the pre-filter masses MECH and MECHpro by EHEIM prove themselves.
FIX by EHEIM is suitable as a separating layer between mechanical and biological filter media.
And for fine filtration at the end, before the water enters the aquarium again, the filter floss SYNTH by EHEIM is ideal.