I have an EheI'm Liberty 2041 which is a hang on back filter. If I'm looking to change the filter media, do I have to get the same filter pads that came with the box, or would the filter work with other types of media like ceramic rings?
More than 10 years
There's three aspects of filtration. Mechanical Which filters out the 'solid' impurities in the water, such as detritus. Mechanical filters are typically a coarse sponge, and sometimes include other media such as ceramic rings as 'pre filters' Biological This is all the beneficial bacteria that converts your ammonia to nitrate (the nitrogen cycle). Biological media is normally in the form of a porous material, can be ceramic rings, purpose designed substratPro (Eheim), BioMax (Fluval), AND in the form of a sponge. Beneficial bacteria will attach to any surface in the aquarium. Chemical Water polishers, medication removers (such as carbon), other specific chemical removers (e.g. Nitrate, Phosphate)
From what I can tell, just looking at the design of the Liberty, it appears EheI'm are using the sponge as both the mechanical and the biological filter (aka typical sponge filter), in addition it appears there is also another rippled pad.
Whilst I believe you could swap the media for cermaic rings, I'm not sure you'd necessarily want to. Sponge filters are fantastic media for beneficial bacteria to grow on, and work really well.