I have an "Aqua Clear" which I like because it has three separate pieces, plastic sponge, Activated carbon (which I no longer use), and the ceramic bio cubes. I can rinse out the sponge and leave the cubes, which keeps me from having minI cycles.
I also have a whisper where the bio floss and carbon are one piece. It looks pretty disgusting, filthy, although I have rinsed it in old tank water. As Gunnie said, I'll replace it only when the water flow is poor and rinsing doesn't work any longer. I have put bio cubes in there too, to help prevent/reduce any minI cycle when I throw it out.
ya I'm surprised wat u guys all like I have a penguin bio-wheel and I just love it my tank is crystal clear I only change the filter insert once a month (could go longer but wana be safe) all the matience I have to do is clean the tube and propeller once a month and I have a whisper b/c htats wat came with the 2.5 gallon and I don't like it at all it doesn't keep the waer that clear and it seems like I hav to change it a lot
I love the aqua-clears they work really wel, I have it on my thirty gallonl. but when I bought my 10 gal. It came with a Whisper 10. Its ok just for that little tank. I also just got a 55 gal. it came with a Whisper 60 I hope it works alright. If it doesn't I'll probably get another aqua clear.
My very favorites are the Marineland Bio-Wheels (in the Eclipse set-ups) and I also have a Whisper filter I like on my quarantine tank. I am going to get some sponge filters to use as supplemental biological filters though.