Change in appearance of tail fin

[Stepht]

New fish owner here..I purchased a half moon betta at the beginning of May. .i noticed in the last 2-3 days that the top of his tail fin is damaged. I haven’t tested water levels up until 2 days ago, which the nitrite level was 3ppm. I’m wondering if this high level is the cause of the damage to his tail, or if there’s something else going on (fin rot?).

He’s in a 5.5gal tank with a top fin silenstream 10 power filter. I’ve got a water bottle “c” set up to help decrease the flow from the filter as my guy doesn’t like the strong flow. I’ve got a water heater set to 78 but sometimes the temp will reach 80 on a warm day. I’m performing weekly water changes, ~10-15%, and using the top fin water conditioner. Feeding pellets (Aqueon) twice daily, and offering bloodworms twice a week (replaces one of the pellet feedings). There aren’t any live plants or other fish in this tank, I never have the tank light on, but the room has good lighting from sun which is not directly on the tank. I purchased Prime conditioner today to replace the top fin one, and bought a vacuum.

Looking for suggestions on how to get these nitrite levels down, and opinions on his tail. Thanks!

First picture is his healthy tail, second picture is what it looks like now, third is tank set up.

 

[Tobiassorensen]

Have you cleaned your filter since start? Did you cycle your tank?

 

[Stepht]

Have you cleaned your filter since start? Did you cycle your tank?

I did not cycle it before putting him in. I kind of jumped into this without knowing much so was t aware it needed to be done. I have changed the filter twice, at the 4 week mark each time. Despite the tail, he’s a super happy guy!

 

[Tobiassorensen]

I did not cycle it before putting him in. I kind of jumped into this without knowing much so was t aware it needed to be done. I have changed the filter twice, at the 4 week mark each time. Despite the tail, he’s a super happy guy!

Well that means you have an nitritespike. Larger wc and no food or little food for some time until you have ammonia 0 nitrite 0 and some amount of nitrate.

Do you have any biomedia in your filter or only floss in them?

 

[Stepht]

I did not cycle it before putting him in. I kind of jumped into this without knowing much so was t aware it needed to be done. I have changed the filter twice, at the 4 week mark each time.

Well that means you have an nitritespike. Larger wc and no food or little food for some time until you have ammonia 0 nitrite 0 and some amount of nitrate.

Do you have any biomedia in your filter or only floss in them?

These are the cartridges I got to go with that specific filter. It states carbon, not sure if that’s the only thing in it?

 

[Tobiassorensen]

Thats just activated carbon. You need biomedia not carbon.

 

[Stepht]

Thats just activated carbon. You need biomedia not carbon.

So decreased feeding, add biomedia, and larger water changes. Does weekly water changes seem sufficient or should it be done more frequently at this time? Also are you suspecting this being the cause of his damaged tail?

 

[Tobiassorensen]

So decreased feeding, add biomedia, and larger water changes. Does weekly water changes seem sufficient or should it be done more frequently at this time? Also are you suspecting this being the cause of his damaged tail?

If it was me i would add biomedia, minimal amounts of food and prob 30% wc every other day.