My cheapo setup to share
simple multi-tier OHF:
Top tray: Wool
Top CD Box: Japanese mat
Middle CD box : Bio Ball on top of CR
Bottom CD box : Bacteria House
Dustbin: CR
120mm sponge filter in the tub
tray and CD boxes are from Daiso $2 each, dustbin $8
weekly wool change and monthly 50% WC
any expert to advise on the arrangement of Filter material?