Sick tiger barbs

Question
I have had two tiger barbs turn white and die. They were in a group of six. before they die, they turn white lay on their sides try to swim occasionaly then slowly die. What is causing this?

Answer
It sounds to me like you may have something frequently called "cotton-mouth" (formal name Columnaris) going on in the tank.  It needs to be treated or all the fish might contract it.  Here is a link for information on this disease:  http://www.americanaquariumproducts.com/Columnaris.html

I would follow the instructions contained in this article as it has very accurate information.  There is also a forum you can join called "Everything Aquatic" at www.everythingaquatic.com.  This is an awesome forum with great people who are always happy to help everyone with any questions/problems they may have.

Good luck.