slow down bub. First things first, it is highly recommended by me and many other nano aquarists that you take out the bio balls. Now, here is what i did, i took out bio balls and top trickle tray. I kept in the bio ball strainer and on top of it i keep a bag of purigen, phosguard and carbon. Where the carbon cartridge was i took out the carbon and filter pad stuff and custom fit a "POly Filtration Pad" to fit on the cartrdge. (cartridges are 12 bucks ea but my lfs sells poly pads 6 bucks ea because i buy in bulk, and poly pads tend to last a little bit longer). If, you want to use filter floss, put it in the middle chamber on the top of everything or on the bottom of everything. For LR rubble, i have heard some great stuff about "seachem matrix", it is rubble sized nitrate mainting media that never needs replacement and (although i dont use it) i know of multiple others who do. I think having LR rubble is rather useless because i have about 10 lbs LR in my tank so i get all my biological filtration from that. Heres how your filter should look no matter what way you do it. Chamber one: cartridge thingy. Chamber 2: all other pads, media, LR rubble, and chaeto. Chamber 3: pump and heater. If you want great filtration tips, find some tank diaries, everyone tells of there filtration methods because so many people ask.
