This is my third betta, I just got him on Saturday. He was in pretty dirty water with lotsa floaters @ the pet store but was beautiful and very spirited. I decided to take him. I added him to my ten gallon tank that still had some water in in from when my last fish passed away many months ago. I cleaned the top where the water evaporated and added new, fresh treated water & heated it up to the right temp.
He has been swimming around but seeming a little lethargic & uninterested in food. From what I have read in another thread the bettas need time to adjust & will not eat right away. I understand that but today I looked closer at my little buddy in the light of day & realized that he had little holes in his bottom fin, pin hole sized. It is not severe but concerning. What do I do? Is this fin rot or something else?