Help Betta's Tail Looks Really Tattered

[SgtTesla]

My betta is a male 2 tail halfmoon, last night I noticed that his tail looked a little tattered. This morning it looked worse, and at lunch the it seemed to be spreading along his fin. I came home tonight and now his other tail is also looking tattered. I haven't added anything to the tank recently, hes been getting regular water changes. His tank is at 76°F, ammonia was at 0ppm when I checked yesterday. Its 5 gallons, filtered, has live plants. Hes been in this tank for 36 days now, what is up with this?? Attaching a bunch of pics,

 

[Salem]

It would help if you filled out this template.

Just going off what you have posted it could be a number of things. I think the most likely are either finrot or his tail is being torn by something- possibly a filter intake.

 

[SgtTesla]

Tank

What is the water volume of the tank?
5 gallons
How long has the tank been running?
41 days
Does it have a filter?
yes
Does it have a heater?
yes
What is the water temperature?
76*F
What is the entire stocking of this tank? (Please list all fish and inverts.)
1 male 2 tail halfmoon betta

Maintenance
How often do you change the water?
3-4 times a week (doing fish in cycle)
How much of the water do you change?
40-50%
What do you use to treat your water?
Seachem Prime
Do you vacuum the substrate or just the water?
substrate and water

*Parameters - Very Important
Did you cycle your tank before adding fish?
No, still cycling tank
What do you use to test the water?
API Freshwater Master Kit & API GH KH test strips
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

Ammonia: 0ppm-0.25ppm
*attached pic below, wasn't sure which*
Nitrite: 0ppm
Nitrate: 0ppm
pH: 6.0

Feeding
How often do you feed your fish?
Every other day
How much do you feed your fish?
~3 flakes in the morning, 3 at night
What brand of food do you feed your fish?
Omega One Betta Buffet Flakes
Do you feed frozen or freeze-dried foods?
Only as a treat, so like once or twice every other week

Illness & Symptoms
How long have you had this fish?
36 days
How long ago did you first notice these symptoms?
yesterday
In a few words, can you explain the symptoms?
His tails look like they're missing chunks
Have you started any treatment for the illness?
No
Was your fish physically ill or injured upon purchase?
Not since I've had him. My aunt had him first though
How has its behavior and appearance changed, if at all?
Behavior: activity level - very active and alert, appetite still good
Appearance: still very colorful, tail fins looking rough as mentioned before

Explain your emergency situation in detail. (Please give a clear explanation of what is going on, include details from the beginning of the illness leading up to now)
Sunday afternoon, I noticed that his tail looked a little off. It looked like it was just missing a little chunk. Monday morning, it looked even worse, but was contained to his lower tail only. I came home for lunch to check on him and his upper tail was also beginning to look shredded. By the time I got home late Monday night, both of his tails were looking bad. (pictures attached above)

 

[SgtTesla]

Also attaching pic of whole tank in case it helps, plants are all live. Stock is 2 java ferns, 1 anubias nana, staurogyene repens, dwarf hair grass, and 1 water wisteria. Hard scape is a cichlid rock with 1 opening up top, 1 betta log (anchors java ferns). He uses both hides a lot.

 

[Salem]

Nothing in there looks too sharp so I'm going to assume it's finrot. Thankfully treating finrot and treating torn fins is pretty similar. Keeping the water clean is concern number one- which you're already taking care of with the multiple water changes a week (though you may have better luck cycling if you do 1-2 changes a week). You can also try giving him aquarium salt baths once a day (or every other day)- I recommend baths over dosing the actual tank with salt because it doesn't evaporate out of the water and it's not really ideal to be in long term. There have also been studies that suggest indian almond leaves have anti-bacterial and anti-fungal qualities along with promoting healing. They will however turn the water sort of a tea-like colour by releasing their tannins into the water (bettas typically like this but the aesthetic isn't for everyone).

 

[SgtTesla]

Thank you for the reply! Bought the salt yesterday and gave him his first bath, he seemed to do fine. I'll try to do that every other day.
Thank you for the tip on the water changes, I tend to veer on the side of caution with my pets. So, I've just been kind of like, 'well the more water changes the less ammonia, less ammonia means less sick fish'. I did do another water change yesterday, but I'll try spacing them out to once or twice a week.
I thought about adding indian almond leaves in, but decided that I liked the look of some of the plants that need a lot of light. I like the natural look of the darker water though, so maybe I'll look into them again.