I heard a noise coming Henry's tank (like he had jumped and broke the surface of the water), and I looked at him, and noticed a gash/hole in his tail fin, and he was kind of freaked out and cautiously looking at the filter.. I also noticed a couple days ago that the tip of his tail fin was missing, and shortly thereafter I noticed about a centimeter missing from his dorsal fin..
I'm not sure whether it's the filter doing this, or his new cave (which I carefully checked for sharp edges before I purchased).
I have unplugged the filter, but I'm a bit hesitant to take out the cave, as he's taken to hiding in it recently (although he does have a plant to hide in, as well).
I'm using (well.. WAS using..) the filter the came with the 2.5 minibow, with pantyhose tied over the intake part so his fins don't get sucked in.. I tried setting up a Red Sea filter when I first got the tank, but couldn't get it to fit properly.. (Did I do something wrong when trying to set up the tank/ filter?)
Can anybody recommend how to treat it?? I feel so bad for him and hope he's not in any pain.. (Do bettas feel pain when their fins tear?)
Thank you so much