Tail damage on Betta Splendens

[Kendall]

Hi, I'm relatively new to keeping siamese fighting fish. I have 4 male betta's in two tanks (with seperator between). I have had them for a couple of monthes now and they have been fine. I have just noticed today that one of my betta's has seem to have lost the ends of his tail i.e. he now has a stubby tail. He does not appear to have anything else visibly worng with this scales or eyes, and the other betta in the other compartment seems fine. Could this be tail-rot? or just damage from the plastic plant? I change 25% of the water every few days and replace with water that has been treated with stress-coat to remove chlorine and a water conditioner that contains various salts. Does anyone have any suggestions as to harmless treatments I could try?
Thanks alot.

 

[Angel Lady]

use some melafix mabey it is good to help them grow back quickly to

 

[my_fallen_angel]

if you thinks its the platic plant remove it a buy real ones they look much nivcer anyways

also add some melafix or bettafix to the tank to help his tail grow back.
Also a little bit of salt wouldnt hurt either