Ok, so my betta fish has fin rot and so I was inspecting him today and his tail was split!! This just happened today. I don't know if it was the fin rot getting worse or.......my filter!?!? I justed added a HOB filter and today I saw my betta lean against it and it would kind of hold his fins and he would have to swim fast to get unstuck, could this have done it? Or was it the fin rot? My tank is 10G with a heater and 2 filters (Tetra Whisper 3i and Aqua-Tech 5-15). The temp is at 79F and I have been doing water changes often due to the fin rot. Tested my water paramaters, nothing, the water is perfect (I use API Freshwater Master Test Kit). Can anyone please help? He is the only fish in the tank so it wasn't nipping, and I only have soft plastic and live plants.