I have a lovely red male betta named Clarence. In the last day or two, I've noticed that on his tail fin and lower fins there are these bands of lighter red, almost pale orange color around the edges. They're about 2mm in width, and aren't ragged at all. I have him in a 2 gallon bowl, with a little rock cave and some gravel on the bottom. It's room temperature (usually between 70 and 73 degrees), freshwater, and I did a 100% water change yesterday. I use API betta water conditioner and NovAqua+ water conditioner. I bought Clarence about three weeks ago from the local PetSmart, where he seemed perfectly healthy, much more active than the other bettas. I'm not sure what the bands are on his fins. Help?