Today I noticed a clear string like thing coming out of (well it looks like it's coming out of) my rainbowfish. The fish is staying on one side of the tank, and appears to be gasping for air. I tested the water and it came out perfect, so it's not that. At first I thought she was pooping, but this thing is clear, and has been hanging there all day now. I had ich in my tank about 3 weeks ago, but it has since cleared up. The tank is 55 gallons and is currently housing 5 rainbow fish, 3 cory's and a small pleco. All other fish seem fine.