white fuzz on mouth

Question
My son has 2 bala sharks and yesterday we noticed that one has a white fuzz looking substance on his mouth. What do you think it is and what can we do? The tank is always kept at about 78 degrees

Answer
Sounds like a fungus. You can get Lifegaurd and use it to cure most illnesses. 78 degrees is fine, but how large is the tank? Bala Sharks (which are actually a large minnow) grow to over 12" long (that's a foot), are territorial, and very fast swimmers. So they will need a 55 gallon tank or larger.