I have an Aquatop CF500-UV canister filter. I have the bottom two trays with sponges / filter floss. The third tray has 2 litres of Seachem Bio and the top tray has pot scrubbies. I have around 4 bags of the ceramic rings left over from AC110's that I no longer use. Would the ceramic rings be much better? I know pot scrubbies are fairly good and the Seachem is good stuff as well.