Pinholes in dorsal fin/betta

Two days ago, I noticed one pinhole in the dorsal fin of my betta. Yesterday, it became a little larger. Today, there is a second one. I'm not sure what's going on-- does anyone have any ideas? You can see these on the top of the V on his back. ET below.






What is the water volume of the tank? 5 gallons
How long has the tank been running? three months
Does it have a filter? yes - internal canister (buffered cascade 300)
Does it have a heater? yes
What is the water temperature? 81o F
What is the entire stocking of this tank? (Please list all fish and inverts.) 1 betta fish, multiple java ferns and java moss, a few frogbit plants. 1 coconut hide

How often do you change the water? 20% to 25% every two to three days
How much of the water do you change? 20% to 25% every two to three days
What do you use to treat your water? Prime
Do you vacuum the substrate or just the water? substrate and water

*Parameters - Very Important
Did you cycle your tank before adding fish? yes
What do you use to test the water? API liquid
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

Ammonia: 0 to .25 - fluctuates (add prime if not 0)
Nitrite: 0
Nitrate: 5
pH LOW: 7.2
pH HIGH: 7.4

How often do you feed your fish? twice a day
How much do you feed your fish? anywhere from 4 to 6 pellets; or small amount of frozen food.
What brand of food do you feed your fish? Northfin pellets (soaked); San Francisco Bay Brand® Freshwater Multi-Pack™ Frozen Fish Food
Do you feed frozen or freeze-dried foods? no freeze-dried; once or twice a week frozen foods

Illness & Symptoms
How long have you had this fish? three months
How long ago did you first notice these symptoms? two days ago
In a few words, can you explain the symptoms? pinholes in dorsal fin, which seem to get larger and a second one showed up this morning
Have you started any treatment for the illness? not yet
Was your fish physically ill or injured upon purchase? not that I am aware of
How has its behavior and appearance changed, if at all? the only thing that has changed in the last week is that he now prefers pellets not be soaked so much.

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) see above




  • Thread Starter
Thought I would bump this and see if anyone has any ideas! I did a water change yesterday, but nothing has changed!
Rose of Sharon
It sounds like you are doing everything right.

Is it possible that he is catching his fin on something in the tank?

For those to pop up just like that sounds like he is trying to squeeze somewhere he shouldn't...

Try to keep an eye on him and see if you can catch him in the act

Just keep up with water changes, and maybe add some Indian almond leaves to your tank. They will help with the healing process and are a natural way to treat problems with betta fins and body issues.
  • Thread Starter
thanks for the feedback. This betta is a little odd compared to the others I've read about; he doesn't like small places or going in things - he prefers to stay in the open. I can't imagine anything in his tank that he would be squeezing through that would catch his fins.

But anyway, I'm planning to do a water change every other day, add in some IAD and hope these work-- there is nothing else I can think of!
Rose of Sharon
I also use Stress Guard by Seachem. It acts like a liquid bandage, and is an anti-septic. I use it with every water change. A bottle will last a long while.

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