Ranchu tail split

[Tan Tran]

Hello everyone, my sakura ranchu has a small split on the tail and it is splitting faster now (I notice it started happening about 5-6 weeks ago). He is normal with eating, swimming. I have something in mind to do for the fish but need your help with better method or recommendations. First, I’m thinking to treat it with methylene blue salt bath, once a day for few days. Second, treat it in a quarantine bucket with maracyn.  Thank you 🙏🏼 
ammonia 0, nitrite 0, nitrate ~40ppm, ph 7.4

here is the link for the video of my fish:

 

 

[Colu]

Is there any Reddening were the tail fins split @Tan Tran

[Tan Tran]

No there isn’t 

[Whitecloud09]

Do you have any sharp decor in the tank @Tan Tran?

[Tan Tran]

No. I have plants river rock and a sponge filter and a canister filter. Nothing is sharp in the tank

[Colu]

Am not seeing any Reddening that would indicate an active infection what I would do is add some Indian almond leaves as they have antibacterial and antifungal properties you might have to add one leaf per gallon to get a beneficial effect and monitor for 7 days if the fins start to recede or you notice any Redding then I would do a course of kanaplex that's a broad spectrum antibiotic treatment @Tan Tran

[Tan Tran]

Thank you @Colu