PuffTheMagicFish

I've sanded down the rocks so the edges aren't actually sharp. All the plants are live. I do 20% water changes about once a week. His fins grow back fine, he just bites them when they get long again 😞 Thanks for your help!

Hi guys, I've had a double tail betta for 1.5 years in a fully planted 10 gallon Walstad-style tank. His only tankmates are red cherry shrimp and nerite snails. There are no sharp edges in his tank. For the past 6 months, he has been biting his tail all the time. There will be round sections gone from his tail/fins that clearly look like fish bites. He has a really hard time swimming when his fins are full length, and I think he gets frustrated. His fins then get infected, I treat him for fin rot, his fins grow back, he bites them again, and the cycle repeats. I have used salt, antibiotics, and stress coat. Is there anything I can do? Tank Parameters: Temp: 76 F pH: 7.5 Ammonia and Nitrites: 0 ppm Nitrates: 5 ppm Thanks!