Betta fish fin cut, help!

[Allysajjad]

Help, my betta fish cut his fin possibly on the artificial plants in tank, it’s his top head fin and cut is kind of deep there was some blood, he’s floating on his side a bit . I did 50% water change and bought some aquarium salt online, how should I treat him. He’s in a three gallon tank, should I put the salt directly in the tank and do a water change 25% daily or do a salt bath in a small container for 15 minutes in aquarium water. How often do I treat him. I also bought some almond leaves should I add those too. I removed all fake plants too

Note- I know a three gallon is small I’m updating him to a 10 gallon soon

 

[GaryE]

It doesn't look like a cut to me. You have a far better view - is there swelling or damage around the base of the fin, where it comes out of the body? It looks like that's there from the photo, but it isn't clear.
It appears like it could be a fatal infection, Mycobacteriosis, a problem with many Bettas. A cut wouldn't cause the problems you describe. As a precaution, don't put your hands in the water if you have open cuts, and wash them well if they're uncut. You might want to use gloves.
I may be wrong - it's just a photo. I hope I'm wrong, because if I'm not, there is no treatment and no cure.

 

[OMG_FL]

Photo isn't clear enough to tell much
But the fish definitely looks stressed
According to your description could be a damaged fin or something else
As a general medication I suggest doing a salt bath

1.Make a salt bath(I don't remember the exact amount of aquarium aslt pwr gallon of water but you can look it up)

2.Make some almond leaves extract (wash the leaves and boil them with some water until a good amount of tannins are extracted and let it cool down to room temp)

3.Prepare two containers with each (dilute the almond leaves extract if needed untill it looks like this

4.Place the betta in the salt bath for 5mins

5.Take him out of the salt and put him in the almond leaves extract also for 5mins

6.Put some almond leaves extract your tank until it looks slightly brown (adding some aquarium salt is fine too but it's a bit harmful for beneficial bacteria too)

7.Put him back in the tank and hope for the best
(Try to give him some antibiotic medicated food if possible but I don't think he'll try to eat at this state)