Neon Tetras - Suspect Hole In The Head

[timolol]

Hi guys

My neons have very recently developed a "ragged" appearance to their heads, like small white things hanging off them or its as if they've been damaged (although they definitely weren't attacked - there's only neon tetras in this tank). Only their heads are affected. I was wondering if neon tetras can be affected by hole in the head disease and if so, is it common? I'm worried for them - they're not looking good. Tank stats are normal and it's 20L.

 

[WILDER]

What are your water stats in ammonia, nitrite, nitrate, and ph.
How many fish and which type.

The tanks to small for neons, they are shoaling fish and shouldn't be kept in anything less than 10 gallon tanks.

Does it look like strands of cotton.
Any pimples on the head.
Does it look like cotton wool on the head.
Is it possible to load a pic up of the sick fish.

Hole in the head start off as a pimple or pitting in the head region.