Honestly, thats what I thought.Lymphocystis.
What's the tank temp and what are you feeding/frequency.
Honestly, I thought that's what it was. But I am new to this so not sure. The water stays at 78 and I feed twice a day. In the morning I feed variety frozen and at night I alternate between flakes and pelletsLymphocystis.
What's the tank temp and what are you feeding/frequency.