No reason you can buy bulk filter media online and cut it to fit. My canister has 5 trays inside and came with a few pads and charcoal. I cut a 2" thick coarse pad for the bottom tray, 1" medium and fine pads for the next tray, charcoal in the third, bio-matrix (Seachem) in the forth, and the top tray I just stuffed full of filter floss.
Next time I clean it the charcoal is gonna go, I'm dropping the current bio-matrix to the third level and putting another full try of bio-matrix in above it. If I need to use charcoal for any reason I'm better off placing it in the AquaClear 110 since it's much easier to replace it there.
>> Jim C. <<