Betta fin shortened?

[BubblesTheBetta]

I have a 6.6 gallon (25L) Fluval Chi with a crowntail betta and a few ghost shrimp. I do weekly water changes of 10-20% and change the filter medai as per manufactureres recommendations. I does every water change with a bacterial supplement (and the Chi has a removalble sponge in the filter to help accumulate beneficial bacteria).

This week I was very busy and did the water change two days late. During these two days my betta seemed to have a slighly decreaed appetite but was still eating a bit, twice a day. When I did the water change I also replaced the filter pad (not the sponge) as it was brown and looked nasty. However, I should note that I did take a few minutes to test my water on the day I was scheduled to do the water change, and everything was within normal and safe ranges.
He perked up a bit after the water change and his appetite returned to normal.

I changed my water on Tuesday, on Wednesday I noticed his tail fin looked different. It appears to be a bit shorter than it used to, but I noticed this first because his anal fin seemed longer than usual.
Is it possible that his anal fin is just growing faster than his tail? Or is it possible that he has something wrong? I looked up fin loss and I don't think that's to blame because his decor hasn't changed in the 3 months i've had him and he frequently plays under the filter without being innjured. I don't see any blackening on the ends, could he still have fin rot?

SORRY FOR THE LONG POST I WANTED TO BE THOROUGH! I AM WORRIED ABOUT MY FISHIE!

 

[HUKIT]

Welcome to the forum,

Sorry your first is post about a potentially sick fish. I'll be honest it doesn't sound like anything to be concerned with but a picture would help. I'd step up the water changes to every other day for a week or so and monitor it from there.

With regards to the bacteria supplement it's a waste of money, just do the water changes and use a quality dechlorinator like Prime and your good to go.