Beta problem

Question
Yesterday I noticed something that looked like cotton "fuzz" under the mouth of our Beta.  By the end of the day he looked like he had a beard and it was spreading to the area of his gills.  This morning he died.  What was the fuzz and will it affect any other fish in the tank?  We have had these fish for only about 10 days.

The tank is 10 gallon and has been active for about 2 months.  I have 3 other small fish a couple of Mollys and an albino catfish.  The water chemistry is good, ammonia between 0 and no more than .25 and nitrite down to 0.

Thanks!

Answer
Hi Ann;

This is a common disease of bettas and as you now know, it can spread very quickly and kill the fish. I call it "Betta Fungus". It can be caused by stress, dirty conditions, injury or cold temperatures.

How long has the tank had fish in it? (The whole 2 months or did it sit empty for a period of time?)
How often do you change water in the tank?
What is the water temperature?
Did it seem he was ever bullied by any other fish?

Let me know as soon as you can.......

Chris Robbins