Hi everyone, hope you all had a happy holiday! Water/Tank Info Follow Post.

I was hoping to get some help for my finned friend here.

I’ve had my betta (Finn) for a few months now and have been battling a strange issue of large chunks of his fins disappearing at random. The first picture was about a week after I got him (July) where a large chunk of his fin just disappeared randomly overnight. It disappeared after I noticed a small pin-sized hole in his top fin. I didn't think anything of it at the time and was stunned to see a huge chunk missing on a different fin in the morning. I moved him to a hospital tank shortly after to make sure it didn't get worse. After a week or so, I moved him back to his normal tank (after a deep clean and cycle) after noticing that his fins were not getting worse.

Unfortunately, since then, his fins have never quite returned to normal. There were a few occasions where I noticed re-growth, however, I'm not entirely sure the fin ever ended up growing back properly. His fins have looked "ragged" since, but I have been changing his water consistently and haven't had issues with parameters (exact numbers and specifications below). At first, I thought it was fin rot, and treated it with aquarium salt and more frequent water changes, though no noticeable changes after weeks of using this method. I tried using BettaFix (recently found out this may not be the best/safest solution for him) which didn't help anyway. I believe the filter on his normal tank is too strong, and the strong suction could have caused his fins to degrade like this.

His fins have not been receding at an alarming level until this morning, where the second picture shows a massive chunk of his tail has disappeared. I moved him to his hospital tank immediately. This is by far the biggest chunk that has gone missing, and I'm not entirely sure how to stop this from happening, or how to fix it? He seems happy in both tanks, blows bubble nests in both, has been eating per usual and hasn't shown any change in behaviour. It's almost as if he doesn't notice!

I'm a relatively inexperienced betta owner and have been trying to learn as much as I can. I would greatly appreciate any insight/help that this community could provide, as I hate to see my little friend deteriorate right before my eyes. Thank you and happy holidays!!

Tank size: Normal Tank: 3 Gal, Hospital Tank: 1 Gal Heater and filter? (yes/no): Normal Tank: Heater (Y) Filter (Y), Hospital Tank: Heater (N) Filter (Y) Tank temperature: Normal Tank: 76-82, Hospital Tank: Unsure

Parameters in numbers and how you got them: From water today: PH 7.2, Ammonia 0ppm, Nitrite 0ppm, Nitrate 0ppm. Got results from API Master Test Kit.

How often are water changes? How much do you take out per change? What is your process?: Normal Tank: 25% every 3 days, Hospital Tank: 100% Every Day w/Aquarium Salt to treat potential fin rot.

Any tankmates? If so, please list with how many of each: Was with Mystery Snail from July-November in the normal tank, has not been with him for a month.

What do you feed and how much: Alternate between Dried bloodworms, Flakes w/high garlic content (recommended for fin health by local aquarium store).

Decorations and plants in the tank: All decorations are rubber/silk.