So I may be over reacting as I just got my betta, and it is my "first". I had one when I was younger but my parent's took care of it as I wasn't old enough/tall enough to change water, feed, etc.
But I digress.
I got a red veil tail 3 days ago. Yesterday (day 2) I decided to change the tank it was in due to the water being too cold. I swapped a .75 gallon tank for a 2 gallon tank with an appropriate sized heater (didn't sleep all night monitoring so he didn't boil
However, starting yesterday I noticed that the tail fin, the middle fin, has a rather pale portion at the end of it. It has gotten more white in the past 24 hours. It was a bit light in the pet store, but I didn't notice anything unusual or alarming at that time, other than the nasty water that he was in (went into fresh water after being acclimated over a 4 hour time span, adding water to his temp container from the new tank slowly eventually replacing it 100%.)
I did the usual google search and it could be fin rot. However I am not sure. The water was changed yesterday, and the day before that as I swapped tanks. I used some of the old stones from the original tank, but I cleaned them in warm water and did several rinses, no soap used. I use stress coat to condition the water, probably should test PH and such, but I'm still learning as I go.
The water temperature is approx. 75-76 degrees F and the only decorations I have is some fake plant leaves to provide cover/shelter and some smooth stones for something different.
I will point out that he eats normally (3-4 pellets of food in 2min) and is very active in the new tank with the heater as before the water was too cold (around 70 which is room temp, I'm in a dorm and don't have much control over this). He is exploratory, active, and generally seems to be in good health otherwise.
Here are a few pictures of him on the 4th, the day I got him:
Here are pictures from the time of this post, the 6th:
Am I being overly cautious or is this something I need to be concerned with. I will be watching it closely and making sure that it doesn't progress but to be sure I am probably getting some salt as I read that 1tsp/gallon seems to help keep this from happening.
However I have done two water changes in two days and I don't want to stress him out too much as that can cause more harm than good.
I haven't even figured out a name for him yet, and I hope that this is something easily cured.