I seen these before floating around and just when I think I got it all after a water change, it comes back. I was wondering if it has anything to do with the Oscar. The Oscar is 8" and he is recovering from HITH from a previous owner. Health wise he appears in good shape except that he hasn't been eating for a couple of weeks. He just recently took some pellets then spit them out (how rude). I had plants in the tank that were falling apart and I cleaned them all out. I even vacuumed the sand and after the water change, I don't see any of these things floating around. Then awhile later, I come back and the tank is full of it. It's like the Oscar is shedding hairs or something. There were a couple of snails in there but they are gone, this was prior to getting the Oscar.