I have a question along the same lines, and I thought I would ask it here. I've been doing a fishless cycle with my tank for the last six weeks (I have a post over in the Nitroge Cycle area of the forum on how it is going). I just got my TSS too, and I get my fish on Friday. The thing is, I've been running my tank with two carbon filters (one in the Cascade, one in the Top Fin.) for the last 7 weeks or so, Should I cut it and dump the carbon and keep the fabric? Or does it not matter because I've had no fish so far?