So my perfect betta that I bought not even a week ago.... His fins are now 'shaggy' looking and the ends are raveled up together and form a point. I have a 10 gallon unheated tank with 2 cories and 3 neon tetras. All live plants and no hard decorations.
What could be causing this? Betta is not sick. I changed the water the last two days 25%. I use the API test kit and the levels are fine. Could it just be too cold? I would say it is about 76 in there. Why would his fins be doing this??? I'm considering buying a heater but I need to know if the tetras, corries, and an amano shrimp would be okay with it.
Forgot to mention he is a very active fishie. There is nothing physically wrong with him that I can see.