I've had a veil tail male betta for a few months now. I was keeping him with a dwarf frog who ended up nipping and tearing his fins, so now I keep them separate. The betta's fins healed quite nicely, but I notice that now his tail fin is starting to separate into like strands. I don't have any sharp plants or anything that would tear his fins, and I am not sure if this is fin rot. I have heard that exessive flaring can cause fin damage. I don't know if this is true or not, but my betta is constantly flaring at my thermometer because the back of it is metal. Do you think the fin damage is due to this flaring? Or could it be fin rot? I will be removing the thermometer for now, just in case.
Thanks in advance.