Got Some Filter Space

[EthanF]

hi guys!
i have just realised that my filter had some zeolight chambers in it, they look like kidneys (sort of ) and i was wondering what does it acctually do ? i could easily remove them and replace them with some filter media of some sort,
 
any suggestions?

 

[KirkyArcher]

What type of filter is it you're using? Spare chambers should really be filled with biological filter media,like Alfagrog or BioHome (sintered glass type media) helps greatly keeping Ammonia and Nitrites down. Zeolite is an ammonia remover that can effectively starve useful forms of bacteria.