Shredded Betta Fish Fins

Hi! I’m new here, but I think this is the template I’m suppose to follow for fish illnesses. Also, I’m not new to keeping betta fish, I’ve had 7 in my lifetime and currently have 3, but I’ve never had this issue before so I’m concerned.

Tank

What is the water volume of the tank?
-5 gallons
How long has the tank been running?
-Almost a year
Does it have a filter?
-Yes
Does it have a heater?
-Yes
What is the water temperature?
-78.8 degrees
What is the entire stocking of this tank? (Please list all fish and inverts.)
-One male betta fish and one mystery snail

Maintenance
How often do you change the water?
-Once a week
How much of the water do you change?
-About a fifth or fourth of the water
What do you use to treat your water?
-Seachem prime
Do you vacuum the substrate or just the water?
-I do vacuum the substrate

*Parameters - Very Important
Did you cycle your tank before adding fish?
-Yes
What do you use to test the water?
-I took a sample to my local aquarium store and paid to have it tested
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

Ammonia: 0
Nitrite: 0
Nitrate: (They didn’t test for this)
pH: 7.4

Feeding
How often do you feed your fish?
-Twice a day
How much do you feed your fish?
-Three northfin betta bits and like a small smidge of either freeze dried daphnia or brine shrimp
What brand of food do you feed your fish?
-northfin/hikari
Do you feed frozen or freeze-dried foods?
-freeze-dried

Illness & Symptoms
How long have you had this fish?
-About a month and two weeks
How long ago did you first notice these symptoms?
-I just noticed them today but to be honest I haven’t been watching that closely
In a few words, can you explain the symptoms?
-His color has shifted (but he’s a koi so I don’t know if it’s just the marbleing gene) and his top fin is terrible shredded like into strips, his end tail fin has like the start of shreds in the middle of it and one of his front pectoral fins is also torn.
Have you started any treatment for the illness?
-no
Was your fish physically ill or injured upon purchase?
-no
How has its behavior and appearance changed, if at all?
-fading of color, but not like to dull to more like clear. His behavior hasn’t changed he still eats fine and swims around. I see him resting on a moss ball sometimes which I didn’t notice before

Explain your emergency situation in detail.
I think I pretty much covered it all above, I just noticed today that his fins are terribly shredded, in my opinion it doesn’t look like fine rot, I don’t see any decoloration (like the black or white tips) and the shredding seemed rather sudden to me. The water parameters are also all fine and I feed him the same/clean his tank the same as my other two fish and neither of their fins are torn? I’m mainly concerned this is some weird disease that might transmit to my other two tanks because I use the same vacuum on all of them.
-I’m going to attempt to attach a photo his fins and a photo of the tank over all! (There’s also a picture of when I first got him for color reference)

 

It is a type of fin rot/melt. It’s happened a few time in my bettas and you need to get control of it fast or it gets really bad pretty quick.

Start with doing 50% water changes daily or at least every other day. If possible, try doing daily methylene blue baths as well. It may be worth adding IAL to his tank from now on.

 

First I'd strongly suggest getting your own test kit (not strips) that tests pH, ammonia, nitrites and nitrates. You need to know what your nitrate levels are. Nitrates can build up over time even with seemingly adequate water changes.
Read-https://www.fishlore.com/NitrogenCycle.htm
Do weekly water changes of 25-50%. That by itself should help prevent fin rot. There is some minor deterioration/ discoloration of the anal and caudal fins and just testing and keeping water extra clean may take care of the fin problem.
The "Indian Almond Leaf" (IAL)Demeter suggested is a good idea.
Indian Almond leaves, some woods, peat moss all leach tannins. Tannins have some antiseptic properties that may help prevent infection and are a natural part of most fishes environment.

 

Demeter Momgoose56

Thank you for the suggestions I’ll start doing the more frequent water changes and see if that helps.
Would the IAL be okay with the mystery snail? I’ve heard they lower pH as well.

 

Demeter Momgoose56

Thank you for the suggestions I’ll start doing the more frequent water changes and see if that helps.
Would the IAL be okay with the mystery snail? I’ve heard they lower pH as well.

Tannins do lower pH a little. What is your pH now? You can ameliorate the effect of the pH drop if necessary (if it's a big drop) by adding a little crushed coral to your filter overflow temporarily.

 

Tannins do lower pH a little. What is your pH now? You can ameliorate the effect of the pH drop if necessary (if it's a big drop) by adding a little crushed coral to your filter overflow temporarily.

It’s 7.4 right now

 

It’s 7.4 right now

You could get some crushed coral, a mesh media bag and your IAL all at once. You'd put 1/2 cup of the coral in the filter overflow compartment for a 5 gallon tank. The coral would actually benefit your snail.