Every once in a while, I see little white worms thinner than a human hair and about 1/4 inch long floating around. About a year ago, I had an infestation, so I broke down the entire tank, cleaned everything, threw out the gravel, and started over, and now I'm seeing them again, but not as abundant. I'm also having problems keeping my water clear. I'm doing 20% changes 3X a week trying to clear it up, and it's gradually getting better. It's a white cloudiness, which is a bacterial imbalance, right? Fish sem to be doing ok, but Oscar isn't as aggressive as usual. Any clues? Especially the little worms?