1~What type of fish is afflicted? Started with Diamond tetras and now Dwarf Neon Rainbos - cotton like stuff on the mouths and heads, no lesions, minor bloating.
2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)? Ammonia 0, Nitrites 0, 2 nitrates, temp 76 F, and 7.2 on PH...