When you look into the more common Betta diseases, you’ll find the source of the problem is very often the result of an unhealthy environment, in other words, a dirty fish tank. Some diseases are contagious, and may be caused by a newly purchased fish introducing a disease into the aquarium, and consequently infecting the others. In this article we’ll take a look at some of the more common diseases, and how they can be treated, or be prevented.