Please fill this out to help us help you;
Tank size:
pH:
ammonia:
nitrite:
nitrate:
kH:
gH:
tank temp:
Fish Symptoms (include full description including lesion, color, location, fish behavior):
Volume and Frequency of water changes:
Chemical Additives or Media in your tank:
Tank inhabitants:
Recent additions to your tank (living or decoration):
Exposure to chemicals:
While I'm not a betta guy, many problems with fish can be traced to water quality. Fresh water is the best preventive medicine around, and in many cases many problems can be solved with large daily water changes.