Betta Fin Loss - Can't Seem to Fix It
My betta fish has been losing his fins fairly rapidly, and I can't seem to figure out what's up. At first I thought it was fin rot - but I took some photos to a local shop that specializes in tropical fish and the owner said it didn't look like fin rot, but rather fin loss. So we've been experimenting with removing some of his plants and gravel (we had originally added some new silk plants that started all of this mess), and now we're back to the original (successful) set up and he's still losing his fins.
The 3 gallon tank generally hovers around a 6.8ph, 0 nitrites or ammonia. It does seem to be a little warm (around 80 degrees) with the heater in it, and we haven't tried removing it yet. We have an active filtration system in there with a carbon filter, and are expecting to get foam padding for the prefilter on Monday from Amazon, as we couldn't find any near us.
I initially did a 100% water change (he lives alone) to start a treatment with aquarium salt (we also use stress coat and betta bowl plus), about two weeks ago, and did 25% changes and vacuumed the gravel daily for a week, but it didn't make much of a difference so we dropped down to 25% changes and vacuuming once a week.
He's acting totally fine, actively swimming to greet us, though he is spending more time resting on the bottom of the tank lately. He's not mopey or anything though. We feed him three betta pellets in the morning and a small dried bloodworm snack in the evening, and he's still eating/chasing after his food/begging.
Any help is appreciated - we've had him for about two months and I just feel really bad for the little guy. I'm attaching images of his tail issues and current tank set up for reference. The light green plants are the ones we removed, as his tail loss started after we added these.