Sorry. It looked like detritus worms. I had 4 bala' s but lost one the other day to septicemea. I don't know why, there is no reason for stress. No bullies in the tank.
The tank is 90 gallons with a 30 gallon sump. However the ph was a little high at 8 but that's it. There are no other fish sick. I quarantined him and used media from his tank to set up another and matched the ph also.